1
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Yu K, Ward TR. C-H functionalization reactions catalyzed by artificial metalloenzymes. J Inorg Biochem 2024; 258:112621. [PMID: 38852295 DOI: 10.1016/j.jinorgbio.2024.112621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/23/2024] [Accepted: 05/25/2024] [Indexed: 06/11/2024]
Abstract
CH functionalization, a promising frontier in modern organic chemistry, facilitates the direct conversion of inert CH bonds into many valuable functional groups. Despite its merits, traditional homogeneous catalysis, often faces challenges in efficiency, selectivity, and sustainability towards this transformation. In this context, artificial metalloenzymes (ArMs), resulting from the incorporation of a catalytically-competent metal cofactor within an evolvable protein scaffold, bridges the gap between the efficiency of enzymatic transformations and the versatility of transition metal catalysis. Accordingly, ArMs have emerged as attractive tools for various challenging catalytic transformations. Additionally, the coming of age of directed evolution has unlocked unprecedented avenues for optimizing enzymatic catalysis. Taking advantage of their genetically-encoded protein scaffold, ArMs have been evolved to catalyze various CH functionalization reactions. This review delves into the recent developments of ArM-catalyzed CH functionalization reactions, highlighting the benefits of engineering the second coordination sphere around a metal cofactor within a host protein.
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Affiliation(s)
- Kun Yu
- Department of Chemistry, University of Basel, Mattenstrasse 22, Basel CH-4058, Switzerland
| | - Thomas R Ward
- Department of Chemistry, University of Basel, Mattenstrasse 22, Basel CH-4058, Switzerland.
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2
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Russo C, Volpe C, Santoro F, Brancaccio D, Di Porzio A, Carotenuto A, Randazzo A, Grimaud L, Vitale MR, Protti S, Giustiniano M. Visible Light-promoted C(sp 3)-H α-Carbamoylation of Cyclic Ethers with Isocyanides. Chemistry 2024; 30:e202401997. [PMID: 38873846 DOI: 10.1002/chem.202401997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/15/2024]
Abstract
A protocol exploiting isocyanides as carbamoylating agents for the α-C(sp3)-H functionalization of cyclic ethers has been optimized via a combined visible light-driven hydrogen atom transfer/Lewis acid-catalyzed approach. The isocyanide substrate scope revealed an exquisite functional group compatibility (18 examples, with yields up to 99 %). Both radical and polar trapping, kinetic isotopic effect and real-time NMR studies support the mechanistic hypothesis and provide insightful details for the design of new chemical processes involving the generation of oxocarbenium ions.
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Affiliation(s)
- Camilla Russo
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Carmine Volpe
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Federica Santoro
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Diego Brancaccio
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Anna Di Porzio
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Laurence Grimaud
- Laboratoire des Biomolécules (LBM), Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Maxime R Vitale
- Laboratoire des Biomolécules (LBM), Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Stefano Protti
- PhotoGreenLab, Department of Chemistry, University of Pavia, viale Taramelli 12, 27100, Pavia, Italy
| | - Mariateresa Giustiniano
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
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3
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Zhang WW, Feng Z, You SL, Zheng C. Electrophile-Arene Affinity: An Energy Scale for Evaluating the Thermodynamics of Electrophilic Dearomatization Reactions. J Org Chem 2024; 89:11487-11501. [PMID: 39077910 DOI: 10.1021/acs.joc.4c01168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Rational design and development of organic reactions are lofty goals in synthetic chemistry. Quantitative description of the properties of molecules and reactions by physical organic parameters plays an important role in this regard. In this Article, we report an energy scale, namely, electrophile-arene affinity (EAA), for evaluating the thermodynamics of electrophilic dearomatization reactions, a class of important transformations that can rapidly build up molecular complexity and structural diversity by converting planar aromatic compounds into three-dimensional cyclic molecules. The acquisition of EAA data can be readily achieved by theoretically calculating the enthalpy changes (ΔH) of the hypothetical reactions of various (cationic) electrophiles with aromatic systems (taking the 1-methylnaphthalen-2-olate ion as an example in this study). Linear correlations are found between the calculated ΔH values and established physical organic parameters such as the percentage of buried volume %VBur (steric effect), Hammett's σ or Brown's σ+ (electronic effect), and Mayr's E (reaction kinetics). Careful analysis of the ΔH values leads to the rational design of a dearomative alkynylation reaction using alkynyl hypervalent iodonium reagents as the electrophiles.
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Affiliation(s)
- Wen-Wen Zhang
- Chang-Kung Chuang Institute, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
| | - Zuolijun Feng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
| | - Shu-Li You
- Chang-Kung Chuang Institute, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
| | - Chao Zheng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
- Shanghai-Hong Kong Joint Laboratory of Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
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4
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Fu K, Yang X, Yu Z, Song L, Shi L. Revealing the nature of covalently tethered distonic radical anions in the generation of heteroatom-centered radicals: evidence for the polarity-matching PCET pathway. Chem Sci 2024; 15:12398-12409. [PMID: 39118625 PMCID: PMC11304808 DOI: 10.1039/d4sc02602k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 06/27/2024] [Indexed: 08/10/2024] Open
Abstract
Recognition of the intermediacy and regulation of reactivity patterns of radical intermediates in radical chemistry have profound impacts on harnessing and developing the full potential of open-shell species in synthetic settings. In this work, the possibility of in situ formation of O/N-X intermediates from Brønsted base covalently tethered carbonyl hypohalites (BCTCs) for the generation of heteroatom-centered radicals has certainly been excluded by NMR experiments and density functional theory calculations. Instead, the spectroscopic analyses reveal that the BCTCs serve as precursors of tether-tunable distonic radical anions (TDRAs) which have been unequivocally substantiated to be involved in the direct cleavage of O/N-H bonds to generate the corresponding heteroatom-centered radicals. Meanwhile, a deep insight into the properties and reactivities of the resulting TDRAs indicates that the introduction of a tethered Brønsted base on the parent open-shell species reinforces their stabilities and leads to a reversal of electrophilicity. Moreover, the dual descriptor values and electrophilicity indices are calculated based on eleven reported radical reactions involving various electrophilic/nucleophilic radical species, further confirming their validity in the prediction of the polar effect and the polarity-matching consistency between nucleophilic TDRAs and protic O/N-H bonds. The additional halogen-free experiments mediated by the combination of phthaloyl peroxide and TEMPO also prove the feasibility of the TDRA-assisted philicity-regulation approach. Lastly, detailed intrinsic bond orbital (IBO) and Hirschfeld spin population analyses are employed to elucidate that the H-atom abstraction processes are the polarity-matching proton-coupled electron transfer (PCET) pathways, with a degree of oxidative asynchronicity.
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Affiliation(s)
- Kang Fu
- School of Chemistry and Chemical Engineering, School of Science(shenzhen), Harbin Institute of Technology Harbin 150001 China
| | - Xihui Yang
- School of Chemistry and Chemical Engineering, School of Science(shenzhen), Harbin Institute of Technology Harbin 150001 China
| | - Zhiyou Yu
- School of Chemistry and Chemical Engineering, School of Science(shenzhen), Harbin Institute of Technology Harbin 150001 China
| | - Lijuan Song
- School of Chemistry and Chemical Engineering, School of Science(shenzhen), Harbin Institute of Technology Harbin 150001 China
| | - Lei Shi
- School of Chemistry and Chemical Engineering, School of Science(shenzhen), Harbin Institute of Technology Harbin 150001 China
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5
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Atkins AP, Dean AC, Lennox AJJ. Benzylic C(sp 3)-H fluorination. Beilstein J Org Chem 2024; 20:1527-1547. [PMID: 39015617 PMCID: PMC11250007 DOI: 10.3762/bjoc.20.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 06/26/2024] [Indexed: 07/18/2024] Open
Abstract
The selective fluorination of C(sp3)-H bonds is an attractive target, particularly for pharmaceutical and agrochemical applications. Consequently, over recent years much attention has been focused on C(sp3)-H fluorination, and several methods that are selective for benzylic C-H bonds have been reported. These protocols operate via several distinct mechanistic pathways and involve a variety of fluorine sources with distinct reactivity profiles. This review aims to give context to these transformations and strategies, highlighting the different tactics to achieve fluorination of benzylic C-H bonds.
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Affiliation(s)
| | - Alice C Dean
- University of Bristol, School of Chemistry, Bristol, BS8 1TS, U.K.
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6
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Chan SC, Palone A, Bietti M, Costas M. tert-Butyl as a Functional Group: Non-Directed Catalytic Hydroxylation of Sterically Congested Primary C-H Bonds. Angew Chem Int Ed Engl 2024; 63:e202402858. [PMID: 38688859 DOI: 10.1002/anie.202402858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/29/2024] [Accepted: 04/30/2024] [Indexed: 05/02/2024]
Abstract
The tert-butyl group is a common aliphatic motif extensively employed to implement steric congestion and conformational rigidity in organic and organometallic molecules. Because of the combination of a high bond dissociation energy (~100 kcal mol-1) and limited accessibility, in the absence of directing groups, neither radical nor organometallic approaches are effective for the chemical modification of tert-butyl C-H bonds. Herein we overcome these limits by employing a highly electrophilic manganese catalyst, [Mn(CF3bpeb)(OTf)2], that operates in the strong hydrogen bond donor solvent nonafluoro-tert-butyl alcohol (NFTBA) and catalytically activates hydrogen peroxide to generate a powerful manganese-oxo species that effectively oxidizes tert-butyl C-H bonds. Leveraging on the interplay of steric, electronic, medium and torsional effects, site-selective and product chemoselective hydroxylation of the tert-butyl group is accomplished with broad reaction scope, delivering primary alcohols as largely dominant products in preparative yields. Late-stage hydroxylation at tert-butyl sites is demonstrated on 6 densely functionalized molecules of pharmaceutical interest. This work uncovers a novel disconnection approach, harnessing tert-butyl as a potential functional group in strategic synthetic planning for complex molecular architectures.
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Affiliation(s)
- Siu-Chung Chan
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, Girona, E-17071, Catalonia, Spain
| | - Andrea Palone
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, Girona, E-17071, Catalonia, Spain
| | - Massimo Bietti
- Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata"; Via della Ricerca Scientifica, 1, I-00133, Rome, Italy
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, Girona, E-17071, Catalonia, Spain
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7
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Baumberger CL, Valley VZ, Chambers MB. Direct photocatalytic C-H functionalization mediated by a molybdenum dioxo complex. Chem Commun (Camb) 2024; 60:6901-6904. [PMID: 38888147 DOI: 10.1039/d4cc01789g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Direct photocatalytic C-H activation mediated by MoO2Cl2(bpy-tBu), a unique photoactive metal OXO, is presented. The limiting step, reoxidation to the Mo dioxo, is evaluated and proposed to occur via a key Cl- loss event. Photocatalyst degradation occurs upon substitution of bpy-tBu with H2O generated during catalysis.
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Affiliation(s)
- Courtney L Baumberger
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA.
| | - Victoria Z Valley
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA.
| | - Matthew B Chambers
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA.
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8
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Liu D, Hazra A, Liu X, Maity R, Tan T, Luo L. CdS Quantum Dot Gels as a Direct Hydrogen Atom Transfer Photocatalyst for C-H Activation. Angew Chem Int Ed Engl 2024:e202403186. [PMID: 38900647 DOI: 10.1002/anie.202403186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/13/2024] [Accepted: 06/19/2024] [Indexed: 06/22/2024]
Abstract
Here, we report CdS quantum dot (QD) gels, a three-dimensional network of interconnected CdS QDs, as a new type of direct hydrogen atom transfer (d-HAT) photocatalyst for C-H activation. We discovered that the photoexcited CdS QD gel could generate various neutral radicals, including α-amido, heterocyclic, acyl, and benzylic radicals, from their corresponding stable molecular substrates, including amides, thio/ethers, aldehydes, and benzylic compounds. Its C-H activation ability imparts a broad substrate and reaction scope. The mechanistic study reveals that this reactivity is intrinsic to CdS materials, and the neutral radical generation did not proceed via the conventional sequential electron transfer and proton transfer pathway. Instead, the C-H bonds are activated by the photoexcited CdS QD gel via a d-HAT mechanism. This d-HAT mechanism is supported by the linear correlation between the logarithm of the C-H bond activation rate constant and the C-H bond dissociation energy (BDE) with a Brønsted slope α=0.5. Our findings expand the currently limited direct hydrogen atom transfer photocatalysis toolbox and provide new possibilities for photocatalytic C-H activation.
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Affiliation(s)
- Daohua Liu
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202
| | - Atanu Hazra
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202
| | - Xiaolong Liu
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100190, China
| | - Rajendra Maity
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202
| | - Ting Tan
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100190, China
| | - Long Luo
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202
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9
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Zhao X, Hou YL, Qian BC, Shen GB. Thermodynamic H-Abstraction Abilities of Nitrogen Centered Radical Cations as Potential Hydrogen Atom Transfer Catalysts in Y-H Bond Functionalization. ACS OMEGA 2024; 9:26708-26718. [PMID: 38911737 PMCID: PMC11191127 DOI: 10.1021/acsomega.4c04209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/25/2024]
Abstract
Y-H bond functionalization has always been the focus of research interest in the area of organic synthesis. Direct hydrogen atom transfer (HAT) from the Y-H bond is one of the most efficient and practical methods to activate the Y-H bond. Recently, nitrogen centered radical cations were broadly utilized as H-abstraction catalysts to activate Y-H bonds via the HAT process. As a type of HAT catalyst, the H-affinity of nitrogen centered radical cations is a significant thermodynamic parameter to quantitatively evaluate the thermodynamic H-abstraction potentials of nitrogen centered radical cations. In this work, the pK a values of 120 protonated N-containing compounds in acetonitrile (AN) are predicted, and the H-affinities of 120 nitrogen centered radical cations in AN are derived from the reduction potentials of nitrogen centered radical cations and pK a of protonated N-containing compounds using Hess' law. This work focuses on the H-abstraction abilities of 120 nitrogen centered radical cations in AN to enrich the molecule library of novel HAT catalysts or H-abstractors and provides valuable thermodynamic guidelines for the application of nitrogen centered radical cations in Y-H bond functionalization.
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Affiliation(s)
- Xia Zhao
- College of Medical Engineering, Jining Medical University, Jining, Shandong 272000, P. R. China
| | - Yi-Lin Hou
- College of Medical Engineering, Jining Medical University, Jining, Shandong 272000, P. R. China
| | - Bao-Chen Qian
- College of Medical Engineering, Jining Medical University, Jining, Shandong 272000, P. R. China
| | - Guang-Bin Shen
- College of Medical Engineering, Jining Medical University, Jining, Shandong 272000, P. R. China
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10
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Venkatraman RK, Tolba AH, Sølling TI, Cibulka R, El-Zohry AM. Ultrafast Events of Photoexcited Iron(III) Chloride for Activation of Benzylic C-H Bonds. J Phys Chem Lett 2024; 15:6202-6208. [PMID: 38836909 DOI: 10.1021/acs.jpclett.4c01116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The usage of rare-earth-metal catalysts in the synthesis of organic compounds is widespread in chemical industries but is limited owing to its environmental and economic costs. However, recent studies indicate that abundant-earth metals like iron(III) chloride can photocatalyze diverse organic transformations using blue-light LEDs. Still, the underlying mechanism behind such activity is debatable and controversial, especially in the absence of ultrafast spectroscopic results. To address this urgent challenge, we performed femtosecond time-resolved electronic absorption spectroscopy experiments of iron(III) chloride in selected organic solvents relevant to its photocatalytic applications. Our results show that the long-lived species [Fe(II) ← Cl•]* is primarily responsible for both oxidizing the organic substrate and reducing molecular oxygen through the diffusion process, leading to the final product and regenerating the photocatalyst rather than the most widely proposed free chloride radical (Cl•). Our study will guide the rational design of efficient earth-abundant photocatalysts.
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Affiliation(s)
- Ravi Kumar Venkatraman
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Amal Hassan Tolba
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
- Chemistry Department, Faculty of Science, Assiut University, Assiut 2074020, Egypt
| | - Theis I Sølling
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Ahmed M El-Zohry
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
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11
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Zhou H, Ruan M, Liu QY, Zhao YX, Wang RY, Yang Y, He SG. Size-dependent reactivity of V nO + ( n = 1-9) clusters with ethane. Phys Chem Chem Phys 2024; 26:14186-14193. [PMID: 38713092 DOI: 10.1039/d4cp00857j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Cost-effective and readily accessible 3d transition metals (TMs) have been considered as promising candidates for alkane activation while 3d TMs especially the early TMs are usually not very reactive with light alkanes. In this study, the reactivity of Vn+ and VnO+ (n = 1-9) cluster cations towards ethane under thermal collision conditions has been investigated using mass spectrometry and density functional theory calculations. Among Vn+ (n = 1-9) clusters, only V3-5+ can react with C2H6 to generate dehydrogenation products and the reaction rate constants are below 10-13 cm3 molecule-1 s-1. In contrast, the reaction rate constants for all VnO+ (n = 1-9) with C2H6 significantly increase by about 2-4 orders of magnitude. Theoretical analysis evidences that the addition of ligand O affects the charge distribution of the metal centers, resulting in a significant increase in the cluster reactivity. The analysis of frontier orbitals indicates that the agostic interaction determines the size-dependent reactivity of VnO+ cluster cations. This study provides a novel approach for improving the reactivity of early 3d TMs.
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Affiliation(s)
- Hang Zhou
- Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Man Ruan
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Qing-Yu Liu
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- Beijing National Laboratory for Molecular Sciences and CAS Research/Education Centre of Excellence in Molecular Sciences, Beijing 100190, P. R. China
| | - Yan-Xia Zhao
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- Beijing National Laboratory for Molecular Sciences and CAS Research/Education Centre of Excellence in Molecular Sciences, Beijing 100190, P. R. China
| | - Rui-Yong Wang
- Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Yuan Yang
- Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
| | - Sheng-Gui He
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- Beijing National Laboratory for Molecular Sciences and CAS Research/Education Centre of Excellence in Molecular Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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12
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Golden DL, Flynn KM, Aikonen S, Hanneman CM, Kalyani D, Krska SW, Paton RS, Stahl SS. Radical Chlorination of Non-Resonant Heterobenzylic C-H Bonds and High-Throughput Diversification of Heterocycles. Chem 2024; 10:1593-1605. [PMID: 39108591 PMCID: PMC11299866 DOI: 10.1016/j.chempr.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Site-selective functionalization of the heterobenzylic C(sp3)-H bonds of pyridines and related heteroaromatic compounds presents challenges associated with the basic nitrogen atom and the variable reactivity among different positions on the heteroaromatic ring. Methods for functionalization of 2- and 4-alkylpyridines are increasingly available through polar pathways that leverage resonance stabilization of charge build-up at these positions. In contrast, functionalization of 3-alkylpyridines is largely inaccessible. Here, we report a photochemically promoted method for chlorination of non-resonant heterobenzylic C(sp3)-H sites in 3-alkylpyridines and related alkylheteroaromatics. Density functional theory calculations show that the optimal reactivity reflects a balance between the energetics of the two radical-chain propagation steps, with the preferred reagent consisting of an N-chlorosulfonamide. The operationally simple chlorination protocol enables access to heterobenzylic chlorides which serve as versatile intermediates in C-H cross-coupling reactions between heteroaromatic building blocks and diverse oxidatively sensitive nucleophiles using high-throughput experimentation.
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Affiliation(s)
- Dung L. Golden
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present address: Chemical Process Development, Bristol Myers Squibb, 556 Morris Avenue, Summit, New Jersey 07901, United States
| | - Kaitlyn M. Flynn
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present address: Drug Substance Development Chemistry, GSK, 1250 Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Santeri Aikonen
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Ft. Collins, Colorado 80523, United States
- Present address: In Silico Discovery, Johnson & Johnson Innovative Medicine, 1400 McKean Road, Spring House, Pennsylvania 19477, United States
| | - Christopher M. Hanneman
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Dipannita Kalyani
- Discovery Chemistry, Merck & Co., Inc., 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
| | - Shane W. Krska
- Discovery Chemistry, Merck & Co., Inc., 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
| | - Robert S. Paton
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Ft. Collins, Colorado 80523, United States
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Lead contact
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13
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Budiman YP, Perutz RN, Steel PG, Radius U, Marder TB. Applications of Transition Metal-Catalyzed ortho-Fluorine-Directed C-H Functionalization of (Poly)fluoroarenes in Organic Synthesis. Chem Rev 2024; 124:4822-4862. [PMID: 38564710 PMCID: PMC11046440 DOI: 10.1021/acs.chemrev.3c00793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/16/2024] [Accepted: 02/22/2024] [Indexed: 04/04/2024]
Abstract
The synthesis of organic compounds efficiently via fewer steps but in higher yields is desirable as this reduces energy and reagent use, waste production, and thus environmental impact as well as cost. The reactivity of C-H bonds ortho to fluorine substituents in (poly)fluoroarenes with metal centers is enhanced relative to meta and para positions. Thus, direct C-H functionalization of (poly)fluoroarenes without prefunctionalization is becoming a significant area of research in organic chemistry. Novel and selective methodologies to functionalize (poly)fluorinated arenes by taking advantage of the reactivity of C-H bonds ortho to C-F bonds are continuously being developed. This review summarizes the reasons for the enhanced reactivity and the consequent developments in the synthesis of valuable (poly)fluoroarene-containing organic compounds.
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Affiliation(s)
- Yudha P. Budiman
- Department
of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, 45363 Sumedang, Indonesia
| | - Robin N. Perutz
- Department
of Chemistry, University of York, York, YO10 5DD, U.K.
| | - Patrick G. Steel
- Department
of Chemistry, University of Durham, Science
Laboratories, South Road, Durham, DH1 3LE, U.K.
| | - Udo Radius
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität
Würzburg, Am Hubland, 97074 Würzburg Germany
| | - Todd B. Marder
- Institute
for Inorganic Chemistry, Julius-Maximilians-Universität
Würzburg, Am Hubland, 97074 Würzburg Germany
- Institute
for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg Germany
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14
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Bakthadoss M, Aina OS, Reddy TT, Izunobi JU, Familoni OB. Mono and di ortho-C-H acetoxylation of 2-aryloxyquinoline-3-carbaldehydes. RSC Adv 2024; 14:13306-13310. [PMID: 38655482 PMCID: PMC11037237 DOI: 10.1039/d4ra01289e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024] Open
Abstract
2-Aryloxyquinolines are well known for various biological activities. In this report, we have developed a novel protocol for introducing an acetoxy functional group on the aryl sp2 carbon of 2-aryloxyquinoline-3-carbaldehyde using a palladium catalyst for the first time. Interestingly, this C-H acetoxylation reaction is highly chemo- and site-selective. By modifying the reaction conditions, mono or di ortho-C-H acetoxylation products have been synthesized selectively with good yields and with good functional group tolerance.
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Affiliation(s)
| | - Oluwafemi S Aina
- Department of Chemistry, Pondicherry University Pondicherry 605 014 India
- Department of Chemistry, University of Lagos Lagos Nigeria
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15
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Sarkar W, LaDuca A, Wilson JR, Szymczak NK. Iron-Catalyzed C-H Oxygenation Using Perchlorate Enabled by Secondary Sphere Hydrogen Bonds. J Am Chem Soc 2024; 146:10508-10516. [PMID: 38564312 PMCID: PMC11137739 DOI: 10.1021/jacs.3c14433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Perchlorate (ClO4-) is a groundwater pollutant that is challenging to remediate. We report a strategy to use Fe(II) tris(2-pyridylmethyl)amine (TPA) complexes featuring appended aniline hydrogen bonds (H-bonds) to promote ClO4- reduction. These complexes facilitate oxygen atom transfer from ClO4- to PPh3 and C-H oxygenation reactions of organic substrates. Catalytic reactions using 15 mol % afforded excellent yields for oxygenation of anthracene and cyclic alkyl aromatics, and this methodology tolerates aryl halides as well as heterocycles containing either O, S, or N.
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Affiliation(s)
- Writhabrata Sarkar
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Andrew LaDuca
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Jessica R Wilson
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Nathaniel K Szymczak
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
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16
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Benítez M, Buil ML, Esteruelas MA, López AM, Martín-Escura C, Oñate E. C-H, N-H, and O-H Bond Activations to Prepare Phosphorescent Hydride-Iridium(III)-Phosphine Emitters with Photocatalytic Achievement in C-C Coupling Reactions. Inorg Chem 2024; 63:6346-6361. [PMID: 38546839 DOI: 10.1021/acs.inorgchem.4c00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Complex IrH5(PiPr3)2 (1) activates two different σ-bonds of 3-phenoxy-1-phenylisoquinoline, 2-(1H-benzimidazol-2-yl)-6-phenylpyridine, 2-(1H-indol-2-yl)-6-phenylpyridine, 2-(2-hydroxyphenyl)-6-phenylpyridine, N-(2-hydroxyphenyl)-N'-phenylimidazolylidene, and 1,3-di(2-pyridyl)-4,6-dimethylbenzene to give IrH{κ3-C,N,C-[C6H4-isoqui-O-C6H4]}(PiPr3)2 (2), IrH{κ3-N,N,C-[NBzim-py-C6H4]}(PiPr3)2 (3), IrH{κ3-N,N,C-[Ind-py-C6H4]}(PiPr3)2 (4), IrH{κ3-C,N,O-[C6H4-py-C6H4O]}(PiPr3)2 (5), IrH{κ3-C,C,O-[C6H4-Im-C6H4O]}(PiPr3)2 (6), and IrH{κ3-N,C,C-[py-C6HMe2-C5H3N]}(PiPr3)2 (7), respectively. The activations are sequential, with the second generally being the slowest. Accordingly, dihydride intermediates IrH2{κ2-C,N-[C6H4-isoqui-O-C6H5]}(PiPr3)2 (2d), IrH2{κ2-N,N-[NBzim-py-C6H5]}(PiPr3)2 (3d), IrH2{κ2-N,N-[Ind-py-C6H5]}(PiPr3)2 (4d), and IrH2{κ2-N,C-[py-C6HMe2-py]}(PiPr3)2 (7d) were characterized spectroscopically. Complexes 3 and 5 are green phosphorescent emitters upon photoexcitation, exhibiting good absorption over a wide range of wavelengths, emission quantum yields about 0.70 in solution, long enough lifetimes (10-17 μs), and reversible electrochemical behavior. In agreement with these features, complex 3 promotes the photocatalytic α-amino C(sp3)-H arylation of N,N-dimethylaniline and N-phenylpiperidine with 1,4-dicyanobenzene and 4-cyanopyridine under blue LED light irradiation. The C-C coupling products are isolated in high yields with only 2 mol % of photocatalyst after 24 h.
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Affiliation(s)
- María Benítez
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
| | - María L Buil
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
| | - Miguel A Esteruelas
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
| | - Ana M López
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
| | - Cristina Martín-Escura
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
| | - Enrique Oñate
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Zaragoza-CSIC, Zaragoza 50009, Spain
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17
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Ju G, Huang Z, Zhao Y. Trialkoxysilane-Induced Iridium-Catalyzed para-Selective C-H Bond Borylation of Arenes. Nat Commun 2024; 15:2847. [PMID: 38565860 PMCID: PMC10987550 DOI: 10.1038/s41467-024-47205-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
An ideal approach for the construction of aryl boron compounds is to selectively replace a C-H bond in arenes with a C-B bond, and controlling regioselectivity is one of the most challenging aspects of these transformations. Herein, we report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective C-H borylation of arenes, including derivatives of benzaldehydes, acetophenones, benzoic acids, benzyl alcohols, phenols, aryl silanes, benzyl silanes, and multi-functionalized aromatic rings are all well tolerated and gave the para -selective C-H borylation products in a short time without the requirement of inert gases atmosphere. The site-selective C-H borylation can be adjustable by installing the developed trialkoxysilane protecting group on different functional groups on one aromatic ring. Importantly, the preparation process of the trialkoxychlorosilane is efficient and scalable. Mechanistic and computational studies reveal that the steric hindrance of the trialkoxysilane protecting group plays a key role in dictating the para-selectivity.
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Affiliation(s)
- Guodong Ju
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Zhibin Huang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Yingsheng Zhao
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453000, China.
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18
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Chai Z. Heterogeneous Photocatalytic Strategies for C(sp 3 )-H Activation. Angew Chem Int Ed Engl 2024; 63:e202316444. [PMID: 38225893 DOI: 10.1002/anie.202316444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/17/2024]
Abstract
Activation of ubiquitous C(sp3 )-H bonds is extremely attractive but remains a great challenge. Heterogeneous photocatalysis offers a promising and sustainable approach for C(sp3 )-H activation and has been fast developing in the past decade. This Minireview focuses on mechanism and strategies for heterogeneous photocatalytic C(sp3 )-H activation. After introducing mechanistic insights, heterogeneous photocatalytic strategies for C(sp3 )-H activation including precise design of active sites, regulation of reactive radical species, improving charge separation and reactor innovations are discussed. In addition, recent advances in C(sp3 )-H activation of hydrocarbons, alcohols, ethers, amines and amides by heterogeneous photocatalysis are summarized. Lastly, challenges and opportunities are outlined to encourage more efforts for the development of this exciting and promising field.
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Affiliation(s)
- Zhigang Chai
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
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19
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Zhu Q, Long J, Song X, Wang K, Zeng J, Fan Y. KO tBu/DMF-Mediated Hydroalkylation of Alkenes via Benzylic C-H Bond Activation. J Org Chem 2024; 89:3726-3731. [PMID: 38417109 DOI: 10.1021/acs.joc.3c02238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
Catalytic hydroalkylation reaction of alkenes with benzylic hydrocarbons involving t-BuOK/DMF-mediated benzylic C-H bond activation is demonstrated. This direct and operational simple protocol affords a rapid and reliable access to a wide scope of benzylic compounds in good-to-excellent yields. The benzylic C-H's of either activated diarylmethanes (pKa ∼ 32.2) and benzyl thioethers (pKa ∼ 30.8) or inert alkylbenzenes could all act as useful synthetic platforms to be conveniently alkylated under mild reaction conditions.
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Affiliation(s)
- Qiming Zhu
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
| | - Jiajia Long
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
| | - Xianchen Song
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
| | - Kaifang Wang
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
| | - Jingkai Zeng
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
| | - Yuyuan Fan
- Institution Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning 530100, P. R. China
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20
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Huang C, Qin YS, Wang CL, Xiao P, Tang S, Liu HJ, Wei Z, Cai H. Visible light-induced C(sp 3)-H azolation of ethers via radical-polar crossover. Chem Commun (Camb) 2024; 60:2669-2672. [PMID: 38351890 DOI: 10.1039/d3cc06210d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
Reported herein is a photochemical strategy for C(sp3)-H azolation of ethers via a hydrogen-atom transfer and radical-polar crossover process, offering efficient access to valuable N-alkylated azoles under visible-light irradiation. The protocol is metal-free and photocatalyst-free, and exhibits good to excellent yields and broad substrate scope with regard to azoles. EPR experiments provide evidence for the formation of intermediates formed in situ.
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Affiliation(s)
- Cheng Huang
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Yu-Shu Qin
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Chen-Lu Wang
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Peng Xiao
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Sheng Tang
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Hong-Jun Liu
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Zhenhong Wei
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
| | - Hu Cai
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
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21
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Xu X, Wang Y, Yu X, Liu X, Hao L, Ji Y. Palladium-Catalyzed (3 + 2) Annulation of Aromatic Acids by C(sp 3)-H Olefination and Decarboxylative Cross-Coupling Reaction. Org Lett 2024; 26:1338-1342. [PMID: 38334428 DOI: 10.1021/acs.orglett.3c04177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
A palladium-catalyzed (3 + 2) annulation of 2-methylbenzoic acid with maleimide using Ac-Leu-OH as a powerful ligand has been reported. Through a site-selective γ-C(sp3)-H olefination reaction and a sequential decarboxylative cross-coupling reaction, a five-membered cyclic ring was obtained as the final product. This novel reaction features great site selectivity and reactivity to generate various cyclic products in moderate to good yields.
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Affiliation(s)
- Xiaobo Xu
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Yangyang Wang
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xiao Yu
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xian Liu
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Liqiang Hao
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Yafei Ji
- Engineering Research Centre of Pharmaceutical Process Chemistry, Ministry of Education; School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
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22
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Tepaske MA, Fitterer A, Verplancke H, Delony D, Neben MC, de Bruin B, Holthausen MC, Schneider S. C-H Bond Activation by Iridium(III) and Iridium(IV) Oxo Complexes. Angew Chem Int Ed Engl 2024; 63:e202316729. [PMID: 38116899 DOI: 10.1002/anie.202316729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
Oxidation of an iridium(III) oxo precursor enabled the structural, spectroscopic, and quantum-chemical characterization of the first well-defined iridium(IV) oxo complex. Side-by-side examination of the proton-coupled electron transfer thermochemistry revealed similar driving forces for the isostructural oxo complexes in two redox states due to compensating contributions from H+ and e- transfer. However, C-H activation of dihydroanthracene revealed significant hydrogen tunneling for the distinctly more basic iridium(III) oxo complex. Our findings complement the growing body of data that relate tunneling to ground state properties as predictors for the selectivity of C-H bond activation.
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Affiliation(s)
- Martijn A Tepaske
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Arnd Fitterer
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Hendrik Verplancke
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Daniel Delony
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Marc C Neben
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Bas de Bruin
- Homogeneous, Supramolecular and Bio-Inspired Catalysis Group, van't Hoff Institute for Molecular Sciences (HIMS), Science Park 904, 1098XH, Amsterdam, The Netherlands
| | - Max C Holthausen
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Sven Schneider
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
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23
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Monirialamdari M, Albrecht A. Decarboxylative photoinduced ligand-to-metal charge transfer reaction: synthesis of 2-substituted chroman-4-ones. Chem Commun (Camb) 2024; 60:1265-1268. [PMID: 38194239 DOI: 10.1039/d3cc05331h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
In this manuscript, a photoinduced ligand-to-metal charge transfer (LMCT) approach, employing transition-metal-based photocatalysts, for the efficient alkylation of electron-poor olefin is described. The developed redox-neutral process benefits from mild reaction conditions and involves a wide range of chromone-3-carboxylic acids as well as nucleophiles amenable to selective C-H functionalization leading to the formation of 2-substituted chroman-4-one compounds with potential biological activity.
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Affiliation(s)
- Mohsen Monirialamdari
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | - Anna Albrecht
- Institute of General and Ecological Chemistry, Faculty of Chemistry, Lodz University of Technology Żeromskiego 116, 90-924 Łódź, Poland.
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24
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Wei Y, Wang Z, Wang K, Qiu JK, Wang Z, Li H, Duan X, Guo K, Bao X, Wu X. Copper-Catalyzed Radical Allene C(sp 2 )-H Cyanation. Angew Chem Int Ed Engl 2024; 63:e202317132. [PMID: 38038249 DOI: 10.1002/anie.202317132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/02/2023]
Abstract
While the hydrogen atom abstraction (HAA) from C(sp3 )-H bond has been well explored, the radical-mediated chemo- and regio-selective functionalization of allenic C(sp2 )-H bond via direct HAA from C(sp2 )-H bond of allene remains an unsolved challenge in synthetic chemistry. This is primarily due to inherent challenges with addition of radical intermediates to allenes, regioselectivity of HAA process, instability of allenyl radical toward propargyl radical et al. Herein, we report a copper catalyzed allenic C(sp2 )-H cyanation of an array of tri- and di-substituted allenes with exceptional site-selectivity, while mono-substituted allene was successfully cyanated, albeit with a low yield. In the developed strategy, steric N-fluoro-N-alkylsulfonamide, serving as precursor of hydrogen atom abstractor, plays a crucial role in achieving the desired regioselectivity and avoiding addition of N-centered radical to allene.
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Affiliation(s)
- Youhao Wei
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Zheng Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Kaifeng Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Jiang-Kai Qiu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zhaoshan Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Haotian Li
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Xiu Duan
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Kai Guo
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Xiaoguang Bao
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
| | - Xinxin Wu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu, 215123, China
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25
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Chen SJ, Krska SW, Stahl SS. Copper-Catalyzed Benzylic C-H Cross-Coupling Enabled by Redox Buffers: Expanding Synthetic Access to Three-Dimensional Chemical Space. Acc Chem Res 2023; 56:3604-3615. [PMID: 38051914 PMCID: PMC10902864 DOI: 10.1021/acs.accounts.3c00580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
ConspectusCross-coupling methods are the most widely used synthetic methods in medicinal chemistry. Existing reactions are dominated by methods such as amide coupling and arylation reactions that form bonds to sp2-hybridized carbon atoms and contribute to the formation of "flat" molecules. Evidence that three-dimensional structures often have improved physicochemical properties for pharmaceutical applications has contributed to growing demand for cross-coupling methods with sp3-hybridized reaction partners. Substituents attached to sp3 carbon atoms are intrinsically displayed in three dimensions. These considerations have led to efforts to establish reactions with sp3 cross-coupling partners, including alkyl halides, amines, alcohols, and carboxylic acids. As C(sp3)-H bonds are much more abundant that these more conventional coupling partners, we have been pursuing C(sp3)-H cross-coupling reactions that achieve site-selectivity, synthetic utility, and scope competitive with conventional coupling reactions.In this Account, we outline Cu-catalyzed oxidative cross-coupling reactions of benzylic C(sp3)-H bonds with diverse nucleophilic partners. These reactions commonly use N-fluorobenzenesulfonimide (NFSI) as the oxidant. The scope of reactivity is greatly improved by using a "redox buffer" that ensures that the Cu catalyst is available in the proper redox state to promote the reaction. Early precedents of catalytic Cu/NFSI oxidative coupling reactions, including C-H cyanation and arylation, did not require a redox buffer, but reactions with other nucleophiles, such as alcohols and azoles, were much less effective under similar conditions. Mechanistic studies show that some nucleophiles, such as cyanide and arylboronic acids, promote in situ reduction of CuII to CuI, contributing to successful catalytic turnover. Poor reactivity was observed with nucleophiles, such as alcohols, that do not promote CuII reduction in the same manner. This insight led to the identification of sacrificial reductants, termed "redox buffers", that support controlled generation of CuI during the reactions and enable successful benzylic C(sp3)-H cross-coupling with diverse nucleophiles. Successful reactions include those that feature direct coupling of (hetero)benzylic C-H substrates with coupling partners (alcohols, azoles) and sequential C(sp3)-H functionalization/coupling reactions. The latter methods feature generation of a synthetic linchpin that can undergo subsequent reaction with a broad array of nucleophiles. For example, halogenation/substitution cascades afford benzylic amines, (thio)ethers, and heterodiarylmethane derivatives, and an isocyanation/amine-addition sequence generates diverse benzylic ureas.Collectively, these Cu-catalyzed (hetero)benzylic C(sp3)-H cross-coupling reactions rapidly access diverse molecules. Analysis of their physicochemical and topological properties highlights the "drug-likeness" and enhanced three-dimensionality of these products relative to existing bioactive molecules. This consideration, together with the high benzylic C-H site-selectivity and the broad scope of reactivity enabled by the redox buffering strategy, makes these C(sp3)-H cross-coupling methods ideally suited for implementation in high-throughput experimentation platforms to explore novel chemical space for drug discovery and related applications.
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Affiliation(s)
- Si-Jie Chen
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave, Madison, Wisconsin, 53706, United States
- Department of Discovery Chemistry, Merck & Co., Inc., 213 E Grand Avenue, South San Francisco, California, 94030, United States
| | - Shane W. Krska
- Department of Discovery Chemistry, Merck & Co., Inc., 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave, Madison, Wisconsin, 53706, United States
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26
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Medvedkov IA, Nikolayev AA, He C, Yang Z, Mebel AM, Kaiser RI. One Collision-Two Substituents: Gas-Phase Preparation of Xylenes under Single-Collision Conditions. Angew Chem Int Ed Engl 2023:e202315147. [PMID: 38072833 DOI: 10.1002/anie.202315147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Indexed: 12/21/2023]
Abstract
The fundamental reaction pathways to the simplest dialkylsubstituted aromatics-xylenes (C6 H4 (CH3 )2 )-in high-temperature combustion flames and in low-temperature extraterrestrial environments are still unknown, but critical to understand the chemistry and molecular mass growth processes in these extreme environments. Exploiting crossed molecular beam experiments augmented by state-of-the-art electronic structure and statistical calculations, this study uncovers a previously elusive, facile gas-phase synthesis of xylenes through an isomer-selective reaction of 1-propynyl (methylethynyl, CH3 CC) with 2-methyl-1,3-butadiene (isoprene, C5 H8 ). The reaction dynamics are driven by a barrierless addition of the radical to the diene moiety of 2-methyl-1,3-butadiene followed by extensive isomerization (hydrogen shifts, cyclization) prior to unimolecular decomposition accompanied by aromatization via atomic hydrogen loss. This overall exoergic reaction affords a preparation of xylenes not only in high-temperature environments such as in combustion flames and around circumstellar envelopes of carbon-rich Asymptotic Giant Branch (AGB) stars, but also in low-temperature cold molecular clouds (10 K) and in hydrocarbon-rich atmospheres of planets and their moons such as Triton and Titan. Our study established a hitherto unknown gas-phase route to xylenes and potentially more complex, disubstituted benzenes via a single collision event highlighting the significance of an alkyl-substituted ethynyl-mediated preparation of aromatic molecules in our Universe.
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Affiliation(s)
- Iakov A Medvedkov
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA
| | | | - Chao He
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA
| | - Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA
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Li H, Zhang Y, Huang Y, Duan P, Ge R, Han X, Zhang W. A Simple Access to γ- and ε-Keto Arenes via Enzymatic Divergent C─H Bond Oxyfunctionalization. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304605. [PMID: 37870171 PMCID: PMC10700168 DOI: 10.1002/advs.202304605] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/28/2023] [Indexed: 10/24/2023]
Abstract
Performing divergent C─H bond functionalization on molecules with multiple reaction sites is a significant challenge in organic chemistry. Biocatalytic oxyfunctionalization reactions of these compounds to the corresponding ketones/aldehydes are typically hindered by selectivity issues. To address these challenges, the catalytic performance of oxidoreductases is explored. The results show that combining the peroxygenase-catalyzed propargylic C─H bond oxidation with the Old Yellow Enzyme-catalyzed reduction of conjugated C─C triple bonds in one-pot enables the regio- and chemoselective oxyfunctionalization of sp3 C─H bonds that are distant from benzylic sites. This enzymatic approach yielded a variety of γ-keto arenes with diverse structural and electronic properties in yields of up to 99% and regioselectivity of 100%, which are difficult to achieve using other chemocatalysis and enzymes. By adjusting the C─C triple bond, the carbonyl group's position can be further tuned to yield ε-keto arenes. This enzymatic approach can be combined with other biocatalysts to establish new synthetic pathways for accessing various challenging divergent C─H bond functionalization reactions.
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Affiliation(s)
- Huanhuan Li
- School of Chemical Engineering and TechnologyXi'an Jiaotong UniversityXi'an710049China
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
| | - Yalan Zhang
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
| | - Yawen Huang
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
| | - Peigao Duan
- School of Chemical Engineering and TechnologyXi'an Jiaotong UniversityXi'an710049China
| | - Ran Ge
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
| | - Xiaofeng Han
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
| | - Wuyuan Zhang
- Key Laboratory of Engineering Biology for Low‐carbon ManufacturingTianjin Institute of Industrial BiotechnologyChinese Academy of Sciences32 West 7th AvenueTianjin300308China
- National Innovation Center for Synthetic Biotechnology32 West 7th AvenueTianjin300308China
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28
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Qiu G, Schreiner PR. The Intrinsic Barrier Width and Its Role in Chemical Reactivity. ACS CENTRAL SCIENCE 2023; 9:2129-2137. [PMID: 38033803 PMCID: PMC10683502 DOI: 10.1021/acscentsci.3c00926] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/29/2023] [Accepted: 10/12/2023] [Indexed: 12/02/2023]
Abstract
Chemical reactions are in virtually all cases understood and explained on the basis of depicting the molecular potential energy landscape, i.e., the change in atomic positions vs the free-energy change. With such landscapes, the features of the reaction barriers solely determine chemical reactivities. The Marcus dissection of the barrier height (activation energy) on such a potential into the thermodynamically independent (intrinsic) and the thermodynamically dependent (Bell-Evans-Polanyi) contributions successfully models the interplay of reaction rate and driving force. This has led to the well-known and ubiquitously used reactivity paradigm of "kinetic versus thermodynamic control". However, an analogous dissection concept regarding the barrier width is absent. Here we define and outline the concept of intrinsic barrier width and the driving force effect on the barrier width and report experimental as well as theoretical studies to demonstrate their distinct roles. We present the idea of changing the barrier widths of conformational isomerizations of some simple aromatic carboxylic acids as models and use quantum mechanical tunneling (QMT) half-lives as a read-out for these changes because QMT is particularly sensitive to barrier widths. We demonstrate the distinct roles of the intrinsic and the thermodynamic contributions of the barrier width on QMT half-lives. This sheds light on resolving conflicting trends in chemical reactivities where barrier widths are relevant and allows us to draw some important conclusions about the general relevance of barrier widths, their qualitative definition, and the consequences for more complete descriptions of chemical reactions.
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Affiliation(s)
- Guanqi Qiu
- Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Peter R. Schreiner
- Institute of Organic Chemistry, Justus Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
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29
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Hosseini S, Beeler JA, Sanford MS, White HS. Electroorganic synthesis in aqueous solution via generation of strongly oxidizing and reducing intermediates. Faraday Discuss 2023; 247:195-208. [PMID: 37492982 DOI: 10.1039/d3fd00067b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Water is the ideal green solvent for organic electrosynthesis. However, a majority of electroorganic processes require potentials that lie beyond the electrochemical window for water. In general, water oxidation and reduction lead to poor synthetic yields and selectivity or altogether prohibit carrying out a desired reaction. Herein, we report several electroorganic reactions in water using synthetic strategies referred to as reductive oxidation and oxidative reduction. Reductive oxidation involves the homogeneous reduction of peroxydisulfate (S2O82-) via electrogenerated Ru(NH3)62+ at potential of -0.2 V vs. Ag/AgCl (3.5 M KCl) to form the highly oxidizing sulfate radical anion (E0' (SO4˙-/SO42-) = 2.21 V vs. Ag/AgCl), which is capable of oxidizing species beyond the water oxidation potential. Electrochemically generated SO4˙- then efficiently abstracts a hydrogen atom from a variety of organic compounds such as benzyl alcohol and toluene to yield product in water. The reverse analogue of reductive oxidation is oxidative reduction. In this case, the homogeneous oxidation of oxalate (C2O42-) by electrochemically generated Ru(bpy)33+ produces the strongly reducing carbon dioxide radical anion (E0' (CO2˙-/CO2) = -2.1 V vs. Ag/AgCl), which can reduce species at potential beyond the water or proton reduction potential. In preliminary studies, the CO2˙- has been used to homogeneously reduce the C-Br moiety belonging to benzyl bromide at an oxidizing potential in aqueous solution.
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Affiliation(s)
| | - Joshua A Beeler
- Department of Chemistry, University of Utah, 315 S 1400 E Salt Lake City, Utah 84112, USA.
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.
| | - Henry S White
- Department of Chemistry, University of Utah, 315 S 1400 E Salt Lake City, Utah 84112, USA.
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30
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Sinha SK, Ghosh P, Jain S, Maiti S, Al-Thabati SA, Alshehri AA, Mokhtar M, Maiti D. Transition-metal catalyzed C-H activation as a means of synthesizing complex natural products. Chem Soc Rev 2023; 52:7461-7503. [PMID: 37811747 DOI: 10.1039/d3cs00282a] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Over the past few decades, the advent of C-H activation has led to a rethink among chemists about the synthetic strategies employed for multi-step transformations. Indeed, deploying innovative and masterful tricks against the numerous classical organic transformations has been the need of the hour. Despite this, the immense importance of C-H activation remains unfulfilled unless the methodology can be deployed for large-scale industrial processes and towards the concise, step-economic synthesis of prodigious natural products and pharmaceutical drugs. Lately, the growing potential of C-H activation methodology has indeed driven the pioneers of synthetic organic chemists into finding more efficient methods to accelerate the synthesis of such complex molecular scaffolds. This review aims to draw a general overview of the various C-H activation procedures that have been adopted for synthesizing these vast majority of structurally complicated natural products. Our objective lies in drawing a complete picture and taking the readers through the synthesis of a series of such complex organic compounds by simplified techniques, making it step-economic on a larger scale and thus instigating the readers to trigger the use of such methodology and uncover new, unique patterns for future synthesis of such natural products.
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Affiliation(s)
- Soumya Kumar Sinha
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Pintu Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Shubhanshu Jain
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Siddhartha Maiti
- School of Biosciences, Engineering and Technology, VIT Bhopal University, Kothrikalan, Sehore, Madhya Pradesh - 466114, India
| | - Shaeel A Al-Thabati
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
| | - Abdulmohsen Ali Alshehri
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
| | - Mohamed Mokhtar
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
| | - Debabrata Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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31
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Ma X, Feng A, Zhang D. Origin of Enantio- and Chemoselectivity in the Synthesis of Spirocycles via Palladium/Xu-Phos-Catalyzed Cascade Heck/Remote C(sp 2)-H Alkylation: A Computational Mechanistic Study. J Phys Chem A 2023; 127:8882-8891. [PMID: 37830770 DOI: 10.1021/acs.jpca.3c05161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Density functional theory (DFT) calculations were performed to study the mechanism and factors affecting the enantio-, regio-, and chemoselectivities in the palladium/Xu-Phos-catalyzed cascade Heck/remote C(sp2)-H alkylation reaction. The active catalyst is found to be able to sustain coordination with P and S atoms and can adapt its coordination mode to accommodate the significant steric hindrance between the ligand and substrate, unlike previous findings that showed coordination with P and O atoms. The reaction is established to occur in sequence through the oxidative addition of the aryl iodide to Pd(0), intramolecular alkene insertion, C(sp2)-H bond activation, and C(sp2)-C(sp3) bond reductive elimination. The C(sp2)-C(sp3) bond reductive elimination is identified as the rate-determining step, and the intramolecular alkene insertion as the enantioselectivity-determining step. The high enantioselectivity originates from the stronger electronic interaction between the catalyst and substrate; the exclusive 5-exo-regioselectivity is due to the stronger nucleophilicity of the terminal alkene carbon atom, and the chemoselectivity of C-H activation over carboiodination is driven by thermodynamics.
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Affiliation(s)
- Xuexiang Ma
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Aili Feng
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
| | - Dongju Zhang
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
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32
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Li QY, Cheng S, Ye Z, Huang T, Yang F, Lin YM, Gong L. Visible light-triggered selective C(sp 2)-H/C(sp 3)-H coupling of benzenes with aliphatic hydrocarbons. Nat Commun 2023; 14:6366. [PMID: 37821440 PMCID: PMC10567795 DOI: 10.1038/s41467-023-42191-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023] Open
Abstract
The direct and selective coupling of benzenes with aliphatic hydrocarbons is a promising strategy for C(sp2)-C(sp3) bond formation using readily available starting materials, yet it remains a significant challenge. In this study, we have developed a simplified photochemical system that incorporates catalytic amounts of iron(III) halides as multifunctional reagents and air as a green oxidant to address this synthetic problem. Under mild conditions, the reaction between a strong C(sp2)-H bond and a robust C(sp3)-H bond has been achieved, affording a broad range of cross-coupling products with high yields and commendable chemo-, site-selectivity. The iron halide acts as a multifunctional reagent that responds to visible light, initiates C-centered radicals, induces single-electron oxidation to carbocations, and participates in a subsequent Friedel-Crafts-type process. The gradual release of radical species and carbocation intermediates appears to be critical for achieving desirable reactivity and selectivity. This eco-friendly, cost-efficient approach offers access to various building blocks from abundant hydrocarbon feedstocks, and demonstrates the potential of iron halides in sustainable synthesis.
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Affiliation(s)
- Qian-Yu Li
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China
| | - Shiyan Cheng
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China
| | - Ziqi Ye
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China
| | - Tao Huang
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China
| | - Fuxing Yang
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China
| | - Yu-Mei Lin
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China.
| | - Lei Gong
- Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, China.
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361005, China.
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33
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Carsch KM, North SC, DiMucci IM, Iliescu A, Vojáčková P, Khazanov T, Zheng SL, Cundari TR, Lancaster KM, Betley TA. Nitrene transfer from a sterically confined copper nitrenoid dipyrrin complex. Chem Sci 2023; 14:10847-10860. [PMID: 37829016 PMCID: PMC10566472 DOI: 10.1039/d3sc03641c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/04/2023] [Indexed: 10/14/2023] Open
Abstract
Despite the myriad Cu-catalyzed nitrene transfer methodologies to form new C-N bonds (e.g., amination, aziridination), the critical reaction intermediates have largely eluded direct characterization due to their inherent reactivity. Herein, we report the synthesis of dipyrrin-supported Cu nitrenoid adducts, investigate their spectroscopic features, and probe their nitrene transfer chemistry through detailed mechanistic analyses. Treatment of the dipyrrin CuI complexes with substituted organoazides affords terminally ligated organoazide adducts with minimal activation of the azide unit as evidenced by vibrational spectroscopy and single crystal X-ray diffraction. The Cu nitrenoid, with an electronic structure most consistent with a triplet nitrene adduct of CuI, is accessed following geometric rearrangement of the azide adduct from κ1-N terminal ligation to κ1-N internal ligation with subsequent expulsion of N2. For perfluorinated arylazides, stoichiometric and catalytic C-H amination and aziridination was observed. Mechanistic analysis employing substrate competition reveals an enthalpically-controlled, electrophilic nitrene transfer for primary and secondary C-H bonds. Kinetic analyses for catalytic amination using tetrahydrofuran as a model substrate reveal pseudo-first order kinetics under relevant amination conditions with a first-order dependence on both Cu and organoazide. Activation parameters determined from Eyring analysis (ΔH‡ = 9.2(2) kcal mol-1, ΔS‡ = -42(2) cal mol-1 K-1, ΔG‡298K = 21.7(2) kcal mol-1) and parallel kinetic isotope effect measurements (1.10(2)) are consistent with rate-limiting Cu nitrenoid formation, followed by a proposed stepwise hydrogen-atom abstraction and rapid radical recombination to furnish the resulting C-N bond. The proposed mechanism and experimental analysis are further corroborated by density functional theory calculations. Multiconfigurational calculations provide insight into the electronic structure of the catalytically relevant Cu nitrene intermediates. The findings presented herein will assist in the development of future methodology for Cu-mediated C-N bond forming catalysis.
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Affiliation(s)
- Kurtis M Carsch
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02138 USA
| | - Sasha C North
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton TX 76203 USA
| | - Ida M DiMucci
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University Ithaca New York 14853 USA
| | - Andrei Iliescu
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02138 USA
| | - Petra Vojáčková
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02138 USA
| | - Thomas Khazanov
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University Ithaca New York 14853 USA
| | - Shao-Liang Zheng
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02138 USA
| | - Thomas R Cundari
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton TX 76203 USA
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University Ithaca New York 14853 USA
| | - Theodore A Betley
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02138 USA
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34
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Shing KP, Qin L, Wu LL, Huang JS, Che CM. Ruthenium(v) terminal arylimido corroles: isolation, spectroscopic characterization and reactivity. Chem Sci 2023; 14:10602-10609. [PMID: 37800003 PMCID: PMC10548528 DOI: 10.1039/d3sc02266h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 08/31/2023] [Indexed: 10/07/2023] Open
Abstract
Terminal Ru(v)-imido species are thought to be as reactive to group transfer reactions as their Ru(v)-oxo homologues, but are less studied. With the electron-rich corrole ligand, relatively stable and isolable Ru(v)-arylimido complexes [Ru(tBu-Cor)(NAr)] (H3(tBu-Cor) = 5,15-diphenyl-10-(p-tert-butylphenyl)corrole, Ar = 2,4,6-Me3C6H2 (Mes), 2,6-(iPr)2C6H3 (Dipp), 2,4,6-(iPr)3C6H2 (Tipp), and 3,5-(CF3)2C6H3 (BTF)) can be prepared from [Ru(tBu-Cor)]2 under strongly reducing conditions. This type of Ru(v)-monoarylimido corrole complex with S = ½ was characterized by high-resolution ESI mass spectrometry, X-band EPR, resonance Raman spectroscopy, magnetic susceptibility, and elemental analysis, together with computational studies. Under heating/light irradiation (xenon lamp) conditions, the complexes [Ru(tBu-Cor)(NAr)] (Ar = Mes, BTF) could undergo aziridination of styrenes and amination of benzylic C(sp3)-H bonds with up to 90% product yields.
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Affiliation(s)
- Ka-Pan Shing
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Lin Qin
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Liang-Liang Wu
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Jie-Sheng Huang
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
| | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong China
- HKU Shenzhen Institute of Research and Innovation Shenzhen China
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35
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de Carvalho RL, Diogo EBT, Homölle SL, Dana S, da Silva Júnior EN, Ackermann L. The crucial role of silver(I)-salts as additives in C-H activation reactions: overall analysis of their versatility and applicability. Chem Soc Rev 2023; 52:6359-6378. [PMID: 37655711 PMCID: PMC10714919 DOI: 10.1039/d3cs00328k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Indexed: 09/02/2023]
Abstract
Transition-metal catalyzed C-H activation reactions have been proven to be useful methodologies for the assembly of synthetically meaningful molecules. This approach bears intrinsic peculiarities that are important to be studied and comprehended in order to achieve its best performance. One example is the use of additives for the in situ generation of catalytically active species. This strategy varies according to the type of additive and the nature of the pre-catalyst that is being used. Thus, silver(I)-salts have proven to play an important role, due to the resulting high reactivity derived from the pre-catalysts of the main transition metals used so far. While being powerful and versatile, the use of silver-based additives can raise concerns, since superstoichiometric amounts of silver(I)-salts are typically required. Therefore, it is crucial to first understand the role of silver(I) salts as additives, in order to wisely overcome this barrier and shift towards silver-free systems.
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Affiliation(s)
- Renato L de Carvalho
- Institute of Exact Sciences, Department of Chemistry, Federal University of Minas Gerais-UFMG, 31270-901, Belo Horizonte, MG, Brazil.
| | - Emilay B T Diogo
- Institute of Exact Sciences, Department of Chemistry, Federal University of Minas Gerais-UFMG, 31270-901, Belo Horizonte, MG, Brazil.
| | - Simon L Homölle
- Institut für Organische und Biomolekulare Chemie and Wöhler Research Institute for Sustainable Chemistry, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
| | - Suman Dana
- Institut für Organische und Biomolekulare Chemie and Wöhler Research Institute for Sustainable Chemistry, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
| | - Eufrânio N da Silva Júnior
- Institute of Exact Sciences, Department of Chemistry, Federal University of Minas Gerais-UFMG, 31270-901, Belo Horizonte, MG, Brazil.
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie and Wöhler Research Institute for Sustainable Chemistry, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
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36
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Zhang LY, Wang NX, Lucan D, Cheung W, Xing Y. Recent Advances in Aerobic Oxidative of C-H Bond by Molecular Oxygen Focus on Heterocycles. Chemistry 2023; 29:e202301700. [PMID: 37390122 DOI: 10.1002/chem.202301700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/02/2023]
Abstract
Aerobic oxidative cross-coupling represents one of the most straightforward and atom-economic methods for construction of C-C and C-X (X=N, O, S, or P) bonds using air as a sustainable external oxidant. The oxidative coupling of C-H bonds in heterocyclic compounds can effectively increase their molecular complexity by introducing new functional groups through C-H bond activation, or by formation of new heterocyclic structures through cascade construction of two or more sequential chemical bonds. This is very useful as it can increase the potential applications of these structures in natural products, pharmaceuticals, agricultural chemicals, and functional materials. This is a representative overview of recent progress since 2010 on green oxidative coupling reactions of C-H bond using O2 or air as internal oxidant focus on Heterocycles. It aims to provide a platform for expanding the scope and utility of air as green oxidant, together with a brief discussion on research into the mechanisms behind it.
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Affiliation(s)
- Lei-Yang Zhang
- Technical Institute of Physics and Chemistry &, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, China
| | - Nai-Xing Wang
- Technical Institute of Physics and Chemistry &, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, China
| | - Dumitra Lucan
- Technical Sciences Academy of Romania ASTR, Dacia Avenue no.26, Bucharest, Romania
| | - William Cheung
- Department of Chemistry, Hofstra University, Hempstead, NY 11549, United States
| | - Yalan Xing
- Department of Chemistry, Hofstra University, Hempstead, NY 11549, United States
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37
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Wang R, Wang CY, Liu P, Bian KJ, Yang C, Wu BB, Wang XS. Enantioselective catalytic radical decarbonylative azidation and cyanation of aldehydes. SCIENCE ADVANCES 2023; 9:eadh5195. [PMID: 37656788 PMCID: PMC10854440 DOI: 10.1126/sciadv.adh5195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/31/2023] [Indexed: 09/03/2023]
Abstract
Empowered by the ubiquity of carbonyl functional groups in organic compounds, decarbonylative functionalization was prevalent in the construction of complex molecules. Under this context, asymmetric decarbonylative functionalization has emerged as an efficient pathway to accessing chiral motifs. However, ablation of enantiomeric control in a conventional 2e transition metal-catalyzed process was notable because of harsh conditions (high temperatures, etc.) that are usually required. To address this challenge and use readily accessible aldehyde directly, we report the asymmetric radical decarbonylative azidation and cyanation. Diverse aldehydes were directly used as alkyl radical precursor, engaging in the subsequent inner-sphere or outer-sphere ligand transfer where functional motifs (CN and N3) could be incorporated in excellent site- and enantioselectivity. Mild conditions, broad scope, excellent regioselectivity (driven by polarity-matching strategy), and enantioselectivity were shown for both transformations. This radical decarbonylative strategy using aldehydes as alkyl radical precursor has offered a powerful reaction manifold in asymmetric radical transformations to construct functional motifs regio- and stereoselectively.
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Affiliation(s)
- Rui Wang
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Cheng-Yu Wang
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Peng Liu
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Kang-Jie Bian
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Chi Yang
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Bing-Bing Wu
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xi-Sheng Wang
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
- State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, P. R. China
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38
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Ma Z, Wu X, Zhu C. Merging Fluorine Incorporation and Functional Group Migration. CHEM REC 2023; 23:e202200221. [PMID: 36367274 DOI: 10.1002/tcr.202200221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/14/2022] [Indexed: 11/13/2022]
Abstract
Fluorine incorporation by concomitant fluoroalkyl radical addition to alkene or alkyne and functional group migration (FGM) represents an ingenious and robust strategy for the synthesis of structurally diverse fluorinated compounds. This account gives an overview of related studies in our group, in which three main reaction modes are discussed: 1) radical fluoroalkylative difunctionalization of unactivated alkenes via intramolecular FGM; 2) alkene difunctionalization by docking-migration process using fluoroalkyl-containing bifunctional reagents; 3) incorporation of fluoroalkyl group into C(sp3 )-H bond via consecutive hydrogen atom transfer (HAT) and FGM. Relying on these methods, a variety of trifluoromethylation and di-/mono-fluoroalkylation reactions along with the migration of cyano, heteroaryl, oximino, formyl, alkynyl, and alkenyl groups have been accomplished under mild conditions.
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Affiliation(s)
- Zhigang Ma
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Xinxin Wu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
| | - Chen Zhu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, Jiangsu, China
- Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, 200240, Shanghai, China
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39
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Wartmann C, Nandi S, Neudörfl JM, Berkessel A. Titanium Salalen Catalyzed Enantioselective Benzylic Hydroxylation. Angew Chem Int Ed Engl 2023; 62:e202306584. [PMID: 37366111 DOI: 10.1002/anie.202306584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
The titanium complex of the cis-1,2-diaminocyclohexane (cis-DACH) derived Berkessel-salalen ligand is a highly efficient and enantioselective catalyst for the asymmetric epoxidation of terminal olefins with hydrogen peroxide ("Berkessel-Katsuki catalyst"). We herein report that this epoxidation catalyst also effects the highly enantioselective hydroxylation of benzylic C-H bonds with hydrogen peroxide. Mechanism-based ligand optimization identified a novel nitro-salalen Ti-catalyst of the highest efficiency ever reported for asymmetric catalytic benzylic hydroxylation, with enantioselectivities of up to 98 % ee, while overoxidation to ketone is marginal. The novel nitro-salalen Ti-catalyst also shows enhanced epoxidation efficiency, as evidenced by e.g. the conversion of 1-decene to its epoxide in 90 % yield with 94 % ee, at a catalyst loading of 0.1 mol-% only.
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Affiliation(s)
- Christina Wartmann
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Shiny Nandi
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Jörg-Martin Neudörfl
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, University of Cologne, Greinstraße 4, 50939, Cologne, Germany
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40
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Maity B, Dutta S, Cavallo L. The mechanism of visible light-induced C-C cross-coupling by C sp3-H bond activation. Chem Soc Rev 2023; 52:5373-5387. [PMID: 37464786 DOI: 10.1039/d2cs00960a] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Csp3-C cross-coupling by activating Csp3-H bonds is a dream reaction for the chemical community, and visible light-induced transition metal-catalysis under mild reaction conditions is considered a powerful tool to achieve it. Advancement of this research area is still in its infancy because of the chemical and technical complexity of this catalysis. Mechanistic studies illuminating the operative reaction pathways can rationalize the increasing amount of experimental catalysis data and provide the knowledge allowing faster and rational advances in the field. This goal requires complementary experimental and theoretical mechanistic studies, as each of them is unfit to clarify the operative mechanisms alone. In this tutorial review we summarize representative experimental and computational mechanistic studies, highlighting weaknesses, strengths, and synergies between the two approaches.
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Affiliation(s)
- Bholanath Maity
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Sayan Dutta
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
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41
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Kim S, Song SL, Zhang J, Kim D, Hong S, Chang S. Regio- and Enantioselective Catalytic δ-C-H Amidation of Dioxazolones Enabled by Open-Shell Copper-Nitrenoid Transfer. J Am Chem Soc 2023; 145:16238-16248. [PMID: 37462685 DOI: 10.1021/jacs.3c05258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Controlling regio- and enantioselectivity in C-H functionalization reactions is of paramount importance due to their versatile synthetic utilities. Herein, we describe a new approach for the asymmetric δ-C(sp3)-H amidation catalysis of dioxazolones using a Cu(I) precursor with a chiral bisoxazoline ligand to access six-membered lactams with high to excellent regio- and enantioselectivity (up to >19:1 rr and >99:1 er). Combined experimental and computational mechanistic studies unveiled that the open-shell character of the postulated Cu-nitrenoids enables the regioselective hydrogen atom abstraction and subsequent enantio-determining radical rebound of the resulting carbon radical intermediates. The synthetic utility of this asymmetric cyclization was demonstrated in the diastereoselective introduction of additional functional groups into the chiral δ-lactam skeleton as well as in the rapid access to biorelevant azacyclic compounds.
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Affiliation(s)
- Suhyeon Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
| | - Se Lin Song
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
| | - Jianbo Zhang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
| | - Dongwook Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
| | - Sungwoo Hong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
| | - Sukbok Chang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, South Korea
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42
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Meng B, Liu L, Shen X, Fan W, Li S. Pyridine N-Oxide-Promoted Cobalt-Catalyzed Dioxygen-Mediated Methane Oxidation. J Org Chem 2023. [PMID: 37486801 DOI: 10.1021/acs.joc.3c00770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
The partial oxidation of methane with O2 is significant due to its potential of providing abundant chemical feedstock. Only a few examples realized this type of reaction in homogeneous solvent systems, most of which are in low efficiency. Herein, we present a pyridine N-oxide-promoted cobalt-catalyzed O2-mediated methane oxidation to produce methylene bis(trifluoroacetate) with productivity over 500 molester molmetal-1 h-1.
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Affiliation(s)
- Bingyin Meng
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China
| | - Luyao Liu
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China
| | - Xiaotong Shen
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China
| | - Wu Fan
- Key Laboratory of Tobacco Flavor Basic Research, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, China
| | - Suhua Li
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China
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43
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Abel-Snape X, Johnson CE, Imbriaco B, Lautens M. Synthesis of spirooxindoles via formal acetylene insertion into a common palladacycle intermediate. Chem Sci 2023; 14:5650-5655. [PMID: 37265736 PMCID: PMC10231318 DOI: 10.1039/d3sc01072d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 04/10/2023] [Indexed: 06/03/2023] Open
Abstract
A palladium-catalyzed spirocyclization reaction is reported, which is proposed to arise via insertion of an oxabicycle into a palladacycle, formed from carbocyclization and a C-H functionalization sequence. Mechanistic studies suggest the insertion is diastereoselective and a post-catalytic retro-Diels-Alder step furnishes an alkene, wherein the oxibicycle has served as an acetylene surrogate. Aryl iodides and carbamoyl chlorides were compatible as starting materials under the same reaction conditions, enabling the convergent and complementary synthesis of spirooxindoles, as well as other azacycles. These spirooxindoles allowed further transformations that were previously unaccessible.
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Affiliation(s)
- Xavier Abel-Snape
- Davenport Laboratories, Department of Chemistry, University of Toronto 80 St. George St. Toronto Ontario M5S 3H6 Canada
| | - Colton E Johnson
- Davenport Laboratories, Department of Chemistry, University of Toronto 80 St. George St. Toronto Ontario M5S 3H6 Canada
| | - Bianca Imbriaco
- Davenport Laboratories, Department of Chemistry, University of Toronto 80 St. George St. Toronto Ontario M5S 3H6 Canada
| | - Mark Lautens
- Davenport Laboratories, Department of Chemistry, University of Toronto 80 St. George St. Toronto Ontario M5S 3H6 Canada
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44
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Golden DL, Zhang C, Chen SJ, Vasilopoulos A, Guzei IA, Stahl SS. Benzylic C-H Esterification with Limiting C-H Substrate Enabled by Photochemical Redox Buffering of the Cu Catalyst. J Am Chem Soc 2023; 145:9434-9440. [PMID: 37084265 PMCID: PMC10510071 DOI: 10.1021/jacs.3c01662] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
Copper-catalyzed radical-relay reactions provide a versatile strategy for selective C-H functionalization; however, reactions with peroxide-based oxidants often require excess C-H substrate. Here, we report a photochemical strategy to overcome this limitation by using a Cu/2,2'-biquinoline catalyst that supports benzylic C-H esterification with limiting C-H substrate. Mechanistic studies indicate that blue-light irradiation promotes carboxylate-to-copper charge transfer, reducing resting-state CuII to CuI, which activates the peroxide to generate an alkoxyl radical hydrogen-atom-transfer species. This "photochemical redox buffering" introduces a unique strategy to sustain the activity of Cu catalysts in radical-relay reactions.
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Affiliation(s)
- Dung L. Golden
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Chaofeng Zhang
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Present Address: Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Si-Jie Chen
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present Address: Department of Discovery Chemistry, Merck & Co., Inc., South San Francisco, California, United States
| | - Aristidis Vasilopoulos
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present Address: AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Ilia A. Guzei
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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45
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Panda C, Anny-Nzekwue O, Doyle LM, Gericke R, McDonald AR. Evidence for a High-Valent Iron-Fluoride That Mediates Oxidative C(sp 3)-H Fluorination. JACS AU 2023; 3:919-928. [PMID: 37006763 PMCID: PMC10052241 DOI: 10.1021/jacsau.3c00021] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 06/19/2023]
Abstract
[FeII(NCCH3)(NTB)](OTf)2 (NTB = tris(2-benzimidazoylmethyl)amine, OTf = trifluoromethanesulfonate) was reacted with difluoro(phenyl)-λ3-iodane (PhIF2) in the presence of a variety of saturated hydrocarbons, resulting in the oxidative fluorination of the hydrocarbons in moderate-to-good yields. Kinetic and product analysis point towards a hydrogen atom transfer oxidation prior to fluorine radical rebound to form the fluorinated product. The combined evidence supports the formation of a formally FeIV(F)2 oxidant that performs hydrogen atom transfer followed by the formation of a dimeric μ-F-(FeIII)2 product that is a plausible fluorine atom transfer rebound reagent. This approach mimics the heme paradigm for hydrocarbon hydroxylation, opening up avenues for oxidative hydrocarbon halogenation.
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46
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Tu JL, Hu AM, Guo L, Xia W. Iron-Catalyzed C(Sp 3)-H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge Transfer. J Am Chem Soc 2023; 145:7600-7611. [PMID: 36958308 DOI: 10.1021/jacs.3c01082] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Catalytic C(sp3)-H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach to this goal. However, the viable substrates utilized in these protocols are limited, and the site selectivity shows preference to activated and thermodynamically favored C(sp3)-H bonds. Herein, we describe the development of undirected iron-catalyzed C(sp3)-H borylation, thiolation, and sulfinylation reactions enabled by the photoinduced ligand-to-metal charge transfer (LMCT) process. These reactions exhibit remarkably broad substrate scope (>150 examples in total), and most importantly, all of these three reactions show unconventional regioselectivity, with the occurrence of C(sp3)-H borylation, thiolation, and sulfinylation preferentially at the distal methyl position. The procedures are operationally simple and readily scalable and provide access to high-value products from simple hydrocarbons in one step. Mechanistic studies and control experiments indicate that the afforded site selectivity is not only relevant to the HAT species but also largely affected by the use of boron- and sulfone-based radical acceptors.
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Affiliation(s)
- Jia-Lin Tu
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Ao-Men Hu
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Lin Guo
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wujiong Xia
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
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47
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Schlachta TP, Kühn FE. Cyclic iron tetra N-heterocyclic carbenes: synthesis, properties, reactivity, and catalysis. Chem Soc Rev 2023; 52:2238-2277. [PMID: 36852959 DOI: 10.1039/d2cs01064j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Cyclic iron tetracarbenes are an emerging class of macrocyclic iron N-heterocyclic carbene (NHC) complexes. They can be considered as an organometallic compound class inspired by their heme analogs, however, their electronic properties differ, e.g. due to the very strong σ-donation of the four combined NHCs in equatorial coordination. The ligand framework of iron tetracarbenes can be readily modified, allowing fine-tuning of the structural and electronic properties of the complexes. The properties of iron tetracarbene complexes are discussed quantitatively and correlations are established. The electronic nature of the tetracarbene ligand allows the isolation of uncommon iron(III) and iron(IV) species and reveals a unique reactivity. Iron tetracarbenes are successfully applied in C-H activation, CO2 reduction, aziridination and epoxidation catalysis and mechanisms as well as decomposition pathways are described. This review will help researchers evaluate the structural and electronic properties of their complexes and target their catalyst properties through ligand design.
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Affiliation(s)
- Tim P Schlachta
- Technical University of Munich, School of Natural Sciences, Department of Chemistry and Catalysis Research Center, Molecular Catalysis, Lichtenbergstraße 4, 85748 Garching, Germany.
| | - Fritz E Kühn
- Technical University of Munich, School of Natural Sciences, Department of Chemistry and Catalysis Research Center, Molecular Catalysis, Lichtenbergstraße 4, 85748 Garching, Germany.
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48
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Pati BV, Puthalath NN, Banjare SK, Nanda T, Ravikumar PC. Transition metal-catalyzed C-H/C-C activation and coupling with 1,3-diyne. Org Biomol Chem 2023; 21:2842-2869. [PMID: 36917476 DOI: 10.1039/d3ob00238a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
This review provides a broad overview of the recent developments in the field of transition metal-catalyzed C-H/C-C bond activation and coupling with 1,3-diyne for assembling alkynylated heterocycles, bis-heterocycles, and 1,3-enynes. Transition metal-catalyzed inert bond (C-H/C-C) activation has been the focus of attention among synthetic chemists in recent times. Enormous developments have taken place in C-H/C-C bond activation chemistry in the last two decades. In recent years the use of 2π-unsaturated units as coupling partners for the synthesis of heterocycles through C-H/C-C bond activation and annulation sequence has received immense attention. Among the unsaturated units employed for assembling heterocycles, the use of 1,3-diynes has garnered significant attention due to its ability to render bis-heterocycles in a straightforward manner. The C-H bond activation and coupling with 1,3-diyne has been very much explored in recent years. However, the development of strategies for the use of 1,3-diynes in the analogous C-C bond activation chemistry is less explored. Earlier methods employed to assemble bis-heterocycle used heterocycles that were preformed and pre-functionalized via transition metal-catalyzed coupling reactions. The expensive pre-functionalized halo-heterocycles and sensitive and expensive heterocyclic metal reagents limit its broad application. However, the transition metal-catalyzed C-H activation obviates the need for expensive heterocyclic metal reagents and pre-functionalized halo-heterocycles. The C-H bond activation strategy makes use of C-H bonds as functional groups for effecting the transformation. This renders the overall synthetic sequence both step and cost economic. Hence, this strategy of C-H activation and subsequent reaction with 1,3-diyne could be used for the larger-scale synthesis of chemicals in the pharmaceutical industry. Despite these advances, there is still the possibility of exploration of earth-abundant and cost-effective first-row transition metals (Ni, Cu, Mn. Fe, etc.) for the synthesis of bis-heterocycles. Moreover, the Cp*-ligand-free, simple metal-salt-mediated synthesis of bis-heterocycles is also less explored. Thus, more exploration of reaction conditions for the Cp*-free synthesis of bis-heterocycles is called for. We hope this review will inspire scientists to investigate these unexplored domains.
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Affiliation(s)
- Bedadyuti Vedvyas Pati
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Odisha 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Nitha Nahan Puthalath
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Odisha 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Shyam Kumar Banjare
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Odisha 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Tanmayee Nanda
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Odisha 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Ponneri C Ravikumar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), Odisha 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
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49
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Hu J, Wang S, Li B, Lei A. K 2S 2O 8-Induced [4+2] Annulation of Tertiary Anilines and Alkenes toward Tetrahydroquinolines. Org Lett 2023. [PMID: 36866524 DOI: 10.1021/acs.orglett.2c04335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Due to the unique physicochemical properties of heterocyclic compounds, their construction is one of the central issues in synthetic chemistry. Here, we report a K2S2O8-induced protocol for constructing tetrahydroquinolines from bulk chemicals (alkenes and anilines). The merit of this method has been demonstrated by its operational simplicity, wide scope, mild conditions, and transition-metal-free system.
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Affiliation(s)
- Jianguo Hu
- National Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, Jiangxi, P. R. China.,Academician Workstation, Jiangxi University of Chinese Medicine, Nanchang 330004, Jiangxi, P. R. China
| | - Shengchun Wang
- The Institute for Advanced Studies (IAS) and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China
| | - Bin Li
- Academician Workstation, Jiangxi University of Chinese Medicine, Nanchang 330004, Jiangxi, P. R. China
| | - Aiwen Lei
- National Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, Jiangxi, P. R. China.,The Institute for Advanced Studies (IAS) and College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China
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50
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Knezevic M, Tiefenbacher K. Tweezer-Based C-H Oxidation Catalysts Overriding the Intrinsic Reactivity of Aliphatic Ammonium Substrates. Chemistry 2023; 29:e202203480. [PMID: 36469523 DOI: 10.1002/chem.202203480] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
The site-selective C-H oxygenation of alkyl chains as well as deactivated positions remains a great challenge for chemists. Here, we report the synthesis and application of four new supramolecular tweezer-based oxidation catalysts. They consist of the well-explored M(pdp/mcp) oxidation moiety and a molecular tweezer capable of binding ammonium salts. All catalysts display preferential oxidation of the strongly deactivated C3/C4 positions, however to different degrees. Furthermore, the best performing catalyst Fe(pdp)Twe was explored with an expanded substrate scope. It was demonstrated that the deactivated positions C3/C4 are also preferentially oxidized in these cases.
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Affiliation(s)
- Melina Knezevic
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058, Basel, Switzerland
| | - Konrad Tiefenbacher
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058, Basel, Switzerland.,Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 24, 4058, Basel, Switzerland
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