1
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Danopoulou M, Zorba LP, Karantoni AP, Tzeli D, Vougioukalakis GC. Copper-Catalyzed α-Alkylation of Aryl Acetonitriles with Benzyl Alcohols. J Org Chem 2024; 89:14242-14254. [PMID: 39292689 DOI: 10.1021/acs.joc.4c01662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2024]
Abstract
A highly efficient, in situ formed CuCl2/TMEDA catalytic system (TMEDA = N,N,N',N'-tetramethylethylene-diamine) for the cross-coupling reaction of aryl acetonitriles with benzyl alcohols is reported. This user-friendly protocol, employing a low catalyst loading and a catalytic amount of base, leads to the synthesis of α-alkylated nitriles in up to 99% yield. Experimental mechanistic investigations reveal that the key step of this transformation is the C(sp3)-H functionalization of the alcohol, taking place via a hydrogen atom abstraction, with the simultaneous formation of copper-hydride species. Detailed density functional theory studies shed light on all reaction steps, confirming the catalytic pathway proposed on the basis of the experimental findings.
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Affiliation(s)
- Marianna Danopoulou
- Laboratory of Organic Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Leandros P Zorba
- Laboratory of Organic Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Athanasia P Karantoni
- Laboratory of Physical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece
| | - Demeter Tzeli
- Laboratory of Physical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Vas. Constantinou, 48, 11635 Athens, Greece
| | - Georgios C Vougioukalakis
- Laboratory of Organic Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens, Greece
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2
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An Q, Chang L, Pan H, Zuo Z. Ligand-to-Metal Charge Transfer (LMCT) Catalysis: Harnessing Simple Cerium Catalysts for Selective Functionalization of Inert C-H and C-C Bonds. Acc Chem Res 2024; 57:2915-2927. [PMID: 39291873 DOI: 10.1021/acs.accounts.4c00510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024]
Abstract
ConspectusChemists have long pursued harnessing light energy and photoexcitation processes for synthetic transformations. Ligand-to-metal charge transfer (LMCT) in high-valent metal complexes often triggers bond homolysis, generating oxidized ligand-centered radicals and reduced metal centers. While photoinduced oxidative activations can be enabled, this process, typically seen as photochemical decomposition, remains underexplored in catalytic applications. To mitigate decomposition during LMCT excitation, we developed a catalytic cycle integrating in situ coordination, LMCT, and ligand homolysis to activate ligated alcohols transiently into alkoxy radicals. This catalytic approach leverages Ce(IV) LMCT excitation and highly reactive alkoxy radical intermediates for selective functionalizations of C(sp3)-H and C(sp3)-C(sp3) bonds under mild conditions. In this Account, we discuss these advancements, highlighting the practical utility of cost-effective cerium salts as catalysts and their potential to develop innovative transformations, addressing long-standing synthetic challenges.Selective functionalization of chemically inert C(sp3)-H bonds has long posed a significant challenge. We first detail our research using LMCT-enabled alkoxy radical-mediated hydrogen atom transfer (HAT) processes for selective C(sp3)-H functionalizations. Using readily available CeCl3, we established a general protocol for employing free alcohols in the Barton reaction. By integrating LMCT and HAT catalysis, we introduced a selective photocatalytic strategy for functionalizing feedstock alkanes, converting gaseous hydrocarbons into valuable products. Employing simple cerium salts like Ce(OTf)3 and CeCl3, we achieved selective C-H amination of methane and ethane at ambient temperature, achieving turnover numbers of 2900 and 9700, respectively. This catalytic manifold has been further exploited to address the site-selectivity challenge in the C-H functionalization of linear alkanes. The use of methanol as a cocatalyst enabled preferential functionalization of the most electron-rich sites, achieving a high intrinsic selectivity over 12:1 of secondary vs primary sites in pentane and hexane.Next, we discuss the catalytic utilization of alkoxy-radical-mediated β-scission, a frequently encountered side reaction in HAT transformations, for selective cleavage and functionalization of C-C bonds. The versatility of the LMCT catalytic platform facilitates the generation of alkoxy radicals from various free alcohols. In our initial demonstration of LMCT-enabled C(sp3)-C(sp3) bond activation, we developed a cerium-catalyzed ring-opening and amination of cycloalkanols, providing an effective protocol for cleaving unstrained C-C bonds. This strategy has been successfully applied to various radical cross-coupling processes, leading to innovative transformations such as ring expansions of cycloalkanols, dehydroxymethylative alkylation, amination, alkenylation, and ring expansions of cyclic ketones. These results highlight the synthetic potential of employing LMCT-mediated β-scission and ubiquitous C-C bonds as unconventional functional handles for generating molecular complexity.Lastly, we delve into our mechanistic investigations. Beyond the catalytic application of Ce(IV) LMCT in various transformations, we have undertaken comprehensive mechanistic studies. These investigations encompass characterization of Ce(IV) alkoxide complexes to elucidate their structures, evaluation of their photoactivity and selectivity in radical generation, and elucidation of kinetic pathways associated with transient LMCT excited states. Our research has revealed ultrafast bond homolysis, back electron transfer, and the selectivity of heteroleptic complexes in homolysis, providing crucial insights for advancing LMCT catalysis.
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Affiliation(s)
- Qing An
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Liang Chang
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Hui Pan
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhiwei Zuo
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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3
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Bhatt K, Adili A, Tran AH, Elmallah KM, Ghiviriga I, Seidel D. Photocatalytic Decarboxylative Alkylation of Cyclic Imine-BF 3 Complexes: A Modular Route to Functionalized Azacycles. J Am Chem Soc 2024; 146:26331-26339. [PMID: 39263993 DOI: 10.1021/jacs.4c08754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
Alkyl radicals generated via an acridine photocatalyzed decarboxylation reaction of feedstock carboxylic acids engage with a range of cyclic imine-BF3 complexes to provide α-functionalized azacycles in an operationally simple process. A three-component variant of this transformation incorporating [1.1.1]propellane as an additional reaction partner enables the synthesis of valuable bicyclopentane (BCP)-containing azacycles. Reactions exhibit good functional group compatibility, enabling late-stage modification of complex bioactive molecules.
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Affiliation(s)
- Kamal Bhatt
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Alafate Adili
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Andrew H Tran
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Kamal M Elmallah
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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4
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Kachore A, Aggarwal V, Bala E, Singh H, Guleria S, Sharma S, Pathan S, Saima, Selvaraj M, Assiri MA, Kumar Verma P. Recent Advances in Direct Regioselective C-H Chlorination at Aromatic and Aliphatic. Chem Asian J 2024; 19:e202400391. [PMID: 38825568 DOI: 10.1002/asia.202400391] [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: 04/22/2024] [Revised: 05/31/2024] [Accepted: 05/31/2024] [Indexed: 06/04/2024]
Abstract
Direct installation of key functionalities in a molecule through C-H bond activation is one of the thrust areas as well as challenging task in organic synthesis. Particularly, introduction of chlorine in a molecule imparts additional benefits for further functionalizations as well as improves the electronic behaviour such as lipophilicity and polarity towards drug development process. The chlorinated molecules have also been established as efficient biologically relevant scaffolds. Current manuscript has been focused on the direct installation of the chlorine atom at various aromatic and aliphatic positions to produce functional molecules. The key highlight of the manuscript belongs to the site selectivity (regioselectivity) for the installation of chlorine functionality. Manuscript describes the advanced methods developed for the direct C-H chlorination reactions and further simplified for the chlorination reactions at various positions including aromatic (o-, m-, and p-), benzylic, heteroaromatic, and aliphatic positions. Directing groups (DGs) and the coordination with the catalyst is the key for the enhancement of regioselectivities during direct C-H chlorination reactions.
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Affiliation(s)
- Ankit Kachore
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Varun Aggarwal
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Ekta Bala
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Hemant Singh
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Saksham Guleria
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Sakshi Sharma
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Sameer Pathan
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Saima
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
| | - Manickam Selvaraj
- Department of Chemistry, Faculty of Science, King Khalid University, PO Box 9004, 61413, Abha, Saudi Arabia
- Research Centre for Advanced Materials Science (RCAMS), King Khalid University, PO Box 9004, Abha, 61413, Saudi Arabia
| | - Mohammed A Assiri
- Department of Chemistry, Faculty of Science, King Khalid University, PO Box 9004, 61413, Abha, Saudi Arabia
- Research Centre for Advanced Materials Science (RCAMS), King Khalid University, PO Box 9004, Abha, 61413, Saudi Arabia
| | - Praveen Kumar Verma
- School of Advanced Chemical Sciences, Shoolini University of Biotechnology and Management Sciences, 173229, Solan, H.P., India
- Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospitals, SIMATS, Saveetha University, 600077, Chennai, Tamil Nadu, India
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5
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Wu H, Fujii T, Wang Q, Zhu J. Quaternary Carbon Editing Enabled by Sequential Palladium Migration. J Am Chem Soc 2024; 146:21239-21244. [PMID: 39052260 DOI: 10.1021/jacs.4c07706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Peripheral functionalization of a quaternary carbon via C(sp3)-H bond activation has made significant progress in recent years. However, direct editing of a quaternary carbon through Csp3-Csp3 bond cleavage and refunctionalization of nonstrained acyclic molecules remain underexploited. Herein we report a reaction in which a methyl group attached to a quaternary carbon is shifted to its neighboring secondary carbon with concurrent oxidation of the quaternary C-C single bond to the C═C double bond. Specifically, morpholinyl amide of 2,2-dimethyl alkanoic acids is converted to 2-methylene-3-methyl alkanoic acid derivatives in the presence of a catalytic amount of palladium acetate, Selectfluor and sodium carbonate. Control experiments suggest that the reaction proceeds via a sequence of selective C(sp3)-H activation of the methyl group, oxidation of the resulting C(sp3)-PdII to PdIV intermediate followed by unprecedented 1,3-PdIV migration, 1,2-methyl/PdIV dyotropic rearrangement and finally, β-Hydride elimination. In this domino process, palladium migrates successively from the primary to the secondary and finally to the quaternary carbon, leading to the concurrent functionalization of a primary, a secondary, and a quaternary carbon.
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Affiliation(s)
- Hua Wu
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
- School of Pharmaceutical Sciences, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China
| | - Takuji Fujii
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| | - Qian Wang
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| | - Jieping Zhu
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
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6
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Li B, Yu F, Chen W, Seidel D. Regioselective α-Phosphonylation of Unprotected Alicyclic Amines. Org Lett 2024; 26:5972-5977. [PMID: 38968591 PMCID: PMC11289722 DOI: 10.1021/acs.orglett.4c02037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
Unprotected alicyclic amines undergo α-C-H bond phosphonylation via a two-stage one-pot process involving the oxidation of amine-derived lithium amides with simple ketone oxidants, generating transient imines which are then captured with phosphites or phosphine oxides. Amines with an existing α-substituent undergo regioselective α'-phosphonylation. Amine α-arylation and α'-phosphonylation can be combined, generating a difunctionalized product in a single operation.
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Affiliation(s)
- Bowen Li
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Fuchao Yu
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Weijie Chen
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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7
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Yamada K, Cheung KPS, Gevorgyan V. General Regio- and Diastereoselective Allylic C-H Oxygenation of Internal Alkenes. J Am Chem Soc 2024; 146:18218-18223. [PMID: 38922638 DOI: 10.1021/jacs.4c06421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Branched allylic esters and carboxylates are fundamental motifs prevalent in natural products and drug molecules. The direct allylic C-H oxygenation of internal alkenes represents one of the most straightforward approaches, bypassing the requirement for an allylic leaving group as in the classical Tsuji-Trost reaction. However, current methods suffer from limited scope─often accompanied by selectivity issues─thus hampering further development. Herein we report a photocatalytic platform as a general solution to these problems, enabling the coupling of diverse internal alkenes with carboxylic acids, alcohols, and other O-nucleophiles, typically in a highly regio- and diastereoselective manner.
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Affiliation(s)
- Kyohei Yamada
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, United States
| | - Kelvin Pak Shing Cheung
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, United States
| | - Vladimir Gevorgyan
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, United States
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8
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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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9
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Wang C, Chen Z, Sun J, Tong L, Wang W, Song S, Li J. Sulfonamide-directed site-selective functionalization of unactivated C(sp 3)-H enabled by photocatalytic sequential electron/proton transfer. Nat Commun 2024; 15:5087. [PMID: 38876986 PMCID: PMC11178871 DOI: 10.1038/s41467-024-49337-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/31/2024] [Indexed: 06/16/2024] Open
Abstract
The generation of alkyl radical from C(sp3)-H substrates via hydrogen atom abstraction represents a desirable yet underexplored strategy in alkylation reaction since involving common concerns remain adequately unaddressed, such as the harsh reaction conditions, limited substrate scope, and the employment of noble metal- or photo-catalysts and stoichiometric oxidants. Here, we utilize the synergistic strategy of photoredox and hydrogen atom transfer (HAT) catalysis to accomplish a general and practical functionalization of unactived C(sp3)-H centers with broad reaction scope, high functional group compatibility, and operational simplicity. A combination of validation experiments and density functional theory reveals that the N-centered radicals, generated from free N - H bond in a stepwise electron/proton transfer event, are the key intermediates that enable an intramolecular 1,5-HAT or intermolecular HAT process for nucleophilic carbon-centered radicals formation to achieve heteroarylation, alkylation, amination, cyanation, azidation, trifluoromethylthiolation, halogenation and deuteration. The practical value of this protocol is further demonstrated by the gram-scale synthesis and the late-stage functionalization of natural products and drug derivatives.
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Affiliation(s)
- Chaodong Wang
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Zhi Chen
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Jie Sun
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Luwei Tong
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Wenjian Wang
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Shengjie Song
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China
| | - Jianjun Li
- Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, P. R. of China.
- Taizhou Key Laboratory of Advanced Manufacturing Technology, Taizhou Institute, Zhejiang University of Technology, Taizhou, P. R. of China.
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10
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Zhang Z, Wei F, Wang X, Zhang Y. Pd(0)-Catalyzed Intermolecular Methylene C(sp 3)-H Silylation by Using N-Heterocyclic Carbene Ligands. Org Lett 2024; 26:3586-3590. [PMID: 38651729 DOI: 10.1021/acs.orglett.4c01044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
The direct functionalization of methylene C(sp3)-H bonds is one of the greatest challenges in transition metal-catalyzed C-H activation. Although Pd(0)-catalyzed intramolecular cyclization reactions of methylene C(sp3)-H bonds have been reported, intermolecular functionalization remains to be discovered. Herein, we report the first example of a Pd(0)-catalyzed intermolecular methylene C(sp3)-H functionalization reaction. By use of a N-heterocyclic carbene ligand, the methylene C(sp3)-H bonds of 1-(benzyloxy)-2-iodobenzenes are activated and disilylated with hexamethyldisilane, affording disilylated products.
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Affiliation(s)
- Zhengyang Zhang
- School of Chemical Science and Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Feng Wei
- School of Chemical Science and Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Xuan Wang
- Department of Chemistry, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Yanghui Zhang
- School of Chemical Science and Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
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11
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Li J, Zhong S, Zhou P, Li X, Xie D, Cai Y, Xia Y. Remote Radical Azidation of Unactivated C(sp 3)-H Bonds in Sulfamoyl Azides. Org Lett 2024; 26:3519-3523. [PMID: 38651932 DOI: 10.1021/acs.orglett.4c00862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
An efficient method for remote radical C(sp3)-H azidation at unactivated sites is described. C-H functionalization proceeds via intramolecular 1,5-hydrogen atom transfer to N-centered radicals that are generated via azido group transfer and/or fragmentation. The readily installed sulfamoyl azide serves as both an amidyl radical precursor and an azido source. This reaction features excellent site selectivity for tertiary, secondary, primary, and benzylic C(sp3)-H bonds and exhibits broad functional group compatibility.
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Affiliation(s)
- Jiawei Li
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Sishi Zhong
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Pan Zhou
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Xu Li
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Danyang Xie
- School of Smart Health, Chongqing College of Electronic Engineering, Chongqing 401331, China
| | - Yunfei Cai
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Yong Xia
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
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12
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Mao R, Gao S, Qin ZY, Rogge T, Wu SJ, Li ZQ, Das A, Houk KN, Arnold FH. Biocatalytic, Enantioenriched Primary Amination of Tertiary C-H Bonds. Nat Catal 2024; 7:585-592. [PMID: 39006156 PMCID: PMC11238567 DOI: 10.1038/s41929-024-01149-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 03/15/2024] [Indexed: 07/16/2024]
Abstract
Intermolecular functionalization of tertiary C-H bonds to construct fully substituted stereogenic carbon centers represents a formidable challenge: without the assistance of directing groups, state-of-the-art catalysts struggle to introduce chirality to racemic tertiary sp 3 -carbon centers. Direct asymmetric functionalization of such centers is a worthy reactivity and selectivity goal for modern biocatalysis. Here we present an engineered nitrene transferase (P411-TEA-5274), derived from a bacterial cytochrome P450, that is capable of aminating tertiary C-H bonds to provide chiral α-tertiary primary amines with high efficiency (up to 2300 total turnovers) and selectivity (up to >99% enantiomeric excess (e.e.)). The construction of fully substituted stereocenters with methyl and ethyl groups underscores the enzyme's remarkable selectivity. A comprehensive substrate scope study demonstrates the biocatalyst's compatibility with diverse functional groups and tertiary C-H bonds. Mechanistic studies elucidate how active-site residues distinguish between the enantiomers and enable the enzyme to perform this transformation with excellent enantioselectivity.
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Affiliation(s)
- Runze Mao
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - Shilong Gao
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - Zi-Yang Qin
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - Torben Rogge
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Sophia J. Wu
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - Zi-Qi Li
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - Anuvab Das
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, California 91125, United States
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13
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Liu DH, Pflüger PM, Outlaw A, Lückemeier L, Zhang F, Regan C, Rashidi Nodeh H, Cernak T, Ma J, Glorius F. Late-Stage Saturation of Drug Molecules. J Am Chem Soc 2024; 146:11866-11875. [PMID: 38621677 PMCID: PMC11066876 DOI: 10.1021/jacs.4c00807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/17/2024]
Abstract
The available methods of chemical synthesis have arguably contributed to the prevalence of aromatic rings, such as benzene, toluene, xylene, or pyridine, in modern pharmaceuticals. Many such sp2-carbon-rich fragments are now easy to synthesize using high-quality cross-coupling reactions that click together an ever-expanding menu of commercially available building blocks, but the products are flat and lipophilic, decreasing their odds of becoming marketed drugs. Converting flat aromatic molecules into saturated analogues with a higher fraction of sp3 carbons could improve their medicinal properties and facilitate the invention of safe, efficacious, metabolically stable, and soluble medicines. In this study, we show that aromatic and heteroaromatic drugs can be readily saturated under exceptionally mild rhodium-catalyzed hydrogenation, acid-mediated reduction, or photocatalyzed-hydrogenation conditions, converting sp2 carbon atoms into sp3 carbon atoms and leading to saturated molecules with improved medicinal properties. These methods are productive in diverse pockets of chemical space, producing complex saturated pharmaceuticals bearing a variety of functional groups and three-dimensional architectures. The rhodium-catalyzed method tolerates traces of dimethyl sulfoxide (DMSO) or water, meaning that pharmaceutical compound collections, which are typically stored in wet DMSO, can finally be reformatted for use as substrates for chemical synthesis. This latter application is demonstrated through the late-stage saturation (LSS) of 768 complex and densely functionalized small-molecule drugs.
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Affiliation(s)
- De-Hai Liu
- Frontiers
Science Center for Transformative Molecules, Shanghai Key Laboratory
for Molecular Engineering of Chiral Drugs, School of Chemistry and
Chemical Engineering and Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Philipp M. Pflüger
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität
Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Andrew Outlaw
- Department
of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Lukas Lückemeier
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität
Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Fuhao Zhang
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität
Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Clinton Regan
- Department
of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hamid Rashidi Nodeh
- Department
of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tim Cernak
- Department
of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jiajia Ma
- Frontiers
Science Center for Transformative Molecules, Shanghai Key Laboratory
for Molecular Engineering of Chiral Drugs, School of Chemistry and
Chemical Engineering and Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität
Münster, Corrensstraße 40, 48149 Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität
Münster, Corrensstraße 40, 48149 Münster, Germany
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14
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Cui J, Niu KK, Zhang RZ, Liu H, Yu S, Xing LB. Photocatalytic selective oxidation of toluene under encapsulated air conditions. Chem Commun (Camb) 2024; 60:4310-4313. [PMID: 38533635 DOI: 10.1039/d4cc00915k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Benzaldehydes are indispensable building blocks in chemistry. However, the selective oxidation of toluene to benzaldehyde remains an ongoing challenge due to the low oxidation potential of benzaldehyde compared to toluene. We report herein a mild protocol that combines hydrogen atom transfer (HAT) with encapsulated air conditions and suitable catalyst loading for selective oxidation of toluene with high selectivity as well as good functional-group tolerance and a broad substrate scope for the synthesis of various high-value aromatic aldehydes. Moreover, the compatibility of this reaction with toluene derivatives of bioactive molecules further demonstrated the practicality of this approach. Mechanism studies have demonstrated that the collaboration between the oxygen quantity and the HAT catalytic system has a major impact on the high selectivity of the reaction. This study not only showcases the effectiveness of HAT strategies toward selective oxidation of toluene to benzaldehyde, but also provides an approach to controlling the selectivity of HAT reactions.
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Affiliation(s)
- Jing Cui
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Kai-Kai Niu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Rong-Zhen Zhang
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Hui Liu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Shengsheng Yu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Ling-Bao Xing
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
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15
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Le TV, Ramachandru GG, Daugulis O. Trifluoroethylation and Pentafluoropropylation of C(sp 3)-H Bonds. Chemistry 2024; 30:e202303190. [PMID: 38011542 DOI: 10.1002/chem.202303190] [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: 09/29/2023] [Revised: 11/14/2023] [Accepted: 11/27/2023] [Indexed: 11/29/2023]
Abstract
Polyfluorinated substituents often enhance effectiveness, improve the stability within metabolic processes, and boost the lipophilicity of biologically active compounds. However, methods for their introduction into aliphatic carbon chains remain very limited. A potentially general route to integrate the fluorinated scaffolds into organic molecules involves insertion of fluorine-containing carbenes into C(sp3)-H bonds. The electron-withdrawing characteristics of perfluoroalkyl groups enhances the reactivity of these carbenes which should enable the functionalization of unactivated C(sp3)-H bonds. Curiously, it appears that use of perfluoroalkyl-containing carbenes in alkane C-H functionalization is exceedingly rare. This concept describes photolysis, enzymatic catalysis, and transition metal catalysis as three primary approaches to C(sp3)-H functionalization by trifluoromethylcarbene and its homologues.
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Affiliation(s)
- Thanh V Le
- Department of Chemistry, University of Houston, 3585 Cullen Blvd, Houston, TX, USA
| | - Girish G Ramachandru
- Department of Chemistry, University of Houston, 3585 Cullen Blvd, Houston, TX, USA
| | - Olafs Daugulis
- Department of Chemistry, University of Houston, 3585 Cullen Blvd, Houston, TX, USA
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16
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Chen YB, Liu LG, Wang ZQ, Chang R, Lu X, Zhou B, Ye LW. Enantioselective functionalization of unactivated C(sp 3)-H bonds through copper-catalyzed diyne cyclization by kinetic resolution. Nat Commun 2024; 15:2232. [PMID: 38472194 PMCID: PMC10933314 DOI: 10.1038/s41467-024-46288-7] [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: 11/23/2023] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Site- and stereoselective C-H functionalization is highly challenging in the synthetic chemistry community. Although the chemistry of vinyl cations has been vigorously studied in C(sp3)-H functionalization reactions, the catalytic enantioselective C(sp3)-H functionalization based on vinyl cations, especially for an unactivated C(sp3)-H bond, has scarcely explored. Here, we report an asymmetric copper-catalyzed tandem diyne cyclization/unactivated C(sp3)-H insertion reaction via a kinetic resolution, affording both chiral polycyclic pyrroles and diynes with generally excellent enantioselectivities and excellent selectivity factors (up to 750). Importantly, this reaction demonstrates a metal-catalyzed enantioselective unactivated C(sp3)-H functionalization via vinyl cation and constitutes a kinetic resolution reaction based on diyne cyclization. Theoretical calculations further support the mechanism of vinyl cation-involved C(sp3)-H insertion reaction and elucidate the origin of enantioselectivity.
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Affiliation(s)
- Yang-Bo Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Li-Gao Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Zhe-Qi Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Rong Chang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xin Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Bo Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Long-Wu Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China.
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17
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Brunard E, Boquet V, Saget T, Sosa Carrizo ED, Sircoglou M, Dauban P. Catalyst-Controlled Intermolecular Homobenzylic C(sp 3)-H Amination for the Synthesis of β-Arylethylamines. J Am Chem Soc 2024; 146:5843-5854. [PMID: 38387076 DOI: 10.1021/jacs.3c10964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The combination of a tailored sulfamate with a C4-symmetrical rhodium(II) tetracarboxylate allows to uncover a selective intermolecular amination of unactivated homobenzylic C(sp3)-H bonds. The reaction has a broad scope (>30 examples) and proceeds with a high level of regioselectivity with homobenzylic/benzylic ratio of up to 35:1, thereby providing a direct access to β-arylethylamines that are of utmost interest in medicinal chemistry. Computational investigations evidenced a concerted mechanism, involving an asynchronous transition state. Based on a combined activation strain model and energy decomposition analysis, the regioselectivity of the reaction was found to rely mainly on the degree of orbital interaction between the [Rh2]-nitrene and the C-H bond. The latter is facilitated at the homobenzylic position due to the establishment of specific noncovalent interactions within the catalytic pocket.
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Affiliation(s)
- Erwan Brunard
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Vincent Boquet
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Tanguy Saget
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - E Daiann Sosa Carrizo
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91400 Orsay, France
| | - Marie Sircoglou
- Université Paris-Saclay, CNRS, Institut de Chimie Moléculaire et des Matériaux d'Orsay, 91400 Orsay, France
| | - Philippe Dauban
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
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18
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Niu KK, Cui J, Dong RZ, Yu S, Liu H, Xing LB. Visible-light-mediated direct C3 alkylation of quinoxalin-2(1 H)-ones using alkanes. Chem Commun (Camb) 2024; 60:2409-2412. [PMID: 38323602 DOI: 10.1039/d3cc06285f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Due to the high C-H bond dissociation energy of alkanes, the utilization of alkanes as alkyl radical precursors for C-H functionalization of heteroarenes is synthetically captivating but practically challenging, especially under metal- and photocatalyst-free conditions. We report herein a mild and practical visible-light-mediated method for C-H alkylation of quinoxalin-2(1H)-ones using trifluoroacetic acid as a hydrogen atom transfer reagent and air as an oxidant. This mild protocol was performed under metal- and photocatalyst-free circumstances and presented good functional-group tolerance as well as a broad substrate scope.
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Affiliation(s)
- Kai-Kai Niu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Jing Cui
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Rui-Zhi Dong
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Shengsheng Yu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Hui Liu
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
| | - Ling-Bao Xing
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China.
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19
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Das KM, Pal A, Surya T L, Roy L, Thakur A. Cu(II) Promoted C(sp 3 )-H Activation in Unactivated Cycloalkanes: Oxo-Alkylation of Styrenes to Synthesize β-Disubstituted Ketones. Chemistry 2024; 30:e202303776. [PMID: 38055713 DOI: 10.1002/chem.202303776] [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: 11/14/2023] [Revised: 12/01/2023] [Accepted: 12/03/2023] [Indexed: 12/08/2023]
Abstract
We report the Cu(II) catalyzed synthesis of β-disubstituted ketones from styrene via oxo-alkylation with unactivated cycloalkanes as the alkylating agent in presence of tert-butylhydroperoxide (TBHP) and 1-methylimidazole as oxidant and base respectively. β-disubstituted ketones are known to be synthesized by using either expensive Ru/Ir complexes, or low-cost metal complexes (e. g., Fe, Mn) with activated species like aldehyde, acid, alcohol, or phthalimide derivatives as the alkylating agent, however, use of unactivated cycloalkanes directly as the alkylating agent remains challenging. A wide range of aliphatic C-H substrates as well as various olefinic arenes and heteroarene (35 substrates including 14 new substrates) are well-tolerated in this method. Hammett analysis shed more light on the substitution effect in the olefinic part on the overall mechanism. Furthermore, the controlled experiments, kinetic isotope effect study, and theoretical calculations (DFT) enable us to gain deeper insight of mechanistic intricacies of this new simple and atom-economic methodology.
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Affiliation(s)
- Krishna Mohan Das
- Department of Chemistry, Jadavpur University, Kolkata, 700032, India
| | - Adwitiya Pal
- Department of Chemistry, Jadavpur University, Kolkata, 700032, India
| | - Lakshmi Surya T
- Institute of Chemical Technology Mumbai, IOC Odisha Campus, Bhubaneswar, Odisha, 751013, India
| | - Lisa Roy
- Institute of Chemical Technology Mumbai, IOC Odisha Campus, Bhubaneswar, Odisha, 751013, India
| | - Arunabha Thakur
- Department of Chemistry, Jadavpur University, Kolkata, 700032, India
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20
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Deng Y, Hu Z, Xue J, Yin J, Zhu T, Liu S. Visible-Light-Promoted α-C(sp 3)-H Amination of Ethers with Azoles and Amides. Org Lett 2024; 26:933-938. [PMID: 38241172 DOI: 10.1021/acs.orglett.3c04291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
A visible-light-induced highly efficient C(sp3)-H amination of ethers with amides and azoles has been presented under mild conditions via a nitrogen- and carbon-centered radical coupling process. This protocol successfully utilizes 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tert-butyl nitrite (TBN) as cocatalysts to deliver the aminated products of ethers under aerobic conditions. Notably, the developed reaction features the corresponding products in good yields (up to 93%) with a wide substrate scope. The mechanistic study indicates that C-N bond formation proceeds via a direct radical cross-coupling process. Preliminary biological activity analysis indicates that the resulting products have good and selective inhibitory activity on osteosarcoma (OS) cell lines and are promising for use as hits for drug discovery.
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Affiliation(s)
- Yaqi Deng
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
| | - Zongjing Hu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
| | - Jian Xue
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
| | - Jiabin Yin
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
| | - Tong Zhu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
| | - Shunying Liu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, Shanghai 200062 China
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21
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Shi Q, Kang XW, Liu Z, Sakthivel P, Aman H, Chang R, Yan X, Pang Y, Dai S, Ding B, Ye J. Single-Electron Oxidation-Initiated Enantioselective Hydrosulfonylation of Olefins Enabled by Photoenzymatic Catalysis. J Am Chem Soc 2024; 146:2748-2756. [PMID: 38214454 DOI: 10.1021/jacs.3c12513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Controlling the enantioselectivity of hydrogen atom transfer (HAT) reactions has been a long-standing synthetic challenge. While recent advances on photoenzymatic catalysis have demonstrated the great potential of non-natural photoenzymes, all of the transformations are initiated by single-electron reduction of the substrate, with only one notable exception. Herein, we report an oxidation-initiated photoenzymatic enantioselective hydrosulfonylation of olefins using a novel mutant of gluconobacter ene-reductase (GluER-W100F-W342F). Compared to known photoenzymatic systems, our approach does not rely on the formation of an electron donor-acceptor complex between the substrates and enzyme cofactor and simplifies the reaction system by obviating the addition of a cofactor regeneration mixture. More importantly, the GluER variant exhibits high reactivity and enantioselectivity and a broad substrate scope. Mechanistic studies support the proposed oxidation-initiated mechanism and reveal that a tyrosine-mediated HAT process is involved.
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Affiliation(s)
- Qinglong Shi
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiu-Wen Kang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhiyong Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pandaram Sakthivel
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hasil Aman
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Rui Chang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaoyu Yan
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yubing Pang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shaobo Dai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory on Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bei Ding
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Juntao Ye
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Center for Ultrafast Science and Technology, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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22
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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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23
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Ward RM, Hu Y, Tu NP, Schomaker JM. Solvent Effects on the Chemo- and Site-Selectivity of Transition Metal-Catalyzed Nitrene Transfer Reactions: Alternatives to Chlorinated Solvents. CHEMSUSCHEM 2024; 17:e202300964. [PMID: 37696772 DOI: 10.1002/cssc.202300964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/09/2023] [Accepted: 09/11/2023] [Indexed: 09/13/2023]
Abstract
Transition metal-catalyzed, non-enzymatic nitrene transfer (NT) reactions to selectively transform C-H and C=C bonds to new C-N bonds are a powerful strategy to streamline the preparation of valuable amine building blocks. However, many catalysts for these reactions use environmentally unfriendly solvents that include dichloromethane, chloroform, 1,2-dichloroethane and benzene. We developed a high-throughput experimentation (HTE) protocol for heterogeneous NT reaction mixtures to enable rapid screening of a broad range of solvents for this chemistry. Coupled with the American Chemical Society Pharmaceutical Roundtable (ACSPR) solvent tool, we identified several attractive replacements for chlorinated solvents. Selected catalysts for NT were compared and contrasted using our HTE protocol, including silver supported by N-dentate ligands, dinuclear Rh complexes and Fe/Mn phthalocyanine catalysts.
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Affiliation(s)
- Robert M Ward
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA
| | - Yun Hu
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA
| | - Noah P Tu
- Discovery Chemistry and Technology, AbbVie Inc., 1 N. Waukegan Rd., North Chicago, Illinois, 60064, USA
| | - Jennifer M Schomaker
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA
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24
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Li W, Sun B, Zhang L, Mo F. Visible-Light-Induced Transition-Metal-Free Redox-Neutral Carboxylation of Remote Benzylic C(sp 3)-H Bonds via 1,5-Hydrogen Atom Transfer. J Org Chem 2024; 89:521-526. [PMID: 38088918 DOI: 10.1021/acs.joc.3c02250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
The direct carboxylation of the benzylic C-H bonds under mild conditions is of great importance and is quite challenging. Herein, we report an approach for the carboxylation of remote benzylic C(sp3)-H bonds by integrating the redox-neutral visible-light photoredox catalysis and the nitrogen-centered 1,5-hydrogen atom transfer. The chemical transformation progresses via consecutive single electron transfer, 1,5-hydrogen atom transfer, formation of benzylic carbanion, and nucleophilic attack on the CO2 steps, thereby enabling access to the desired carboxylation products with moderate to high yields. We also endeavor to recover the CO2 groups generated in situ intramolecularly to achieve carboxylation under a nitrogen atmosphere, resulting in moderate yields of corresponding carboxylation.
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Affiliation(s)
- Wenke Li
- College of Engineering, Peking University, Beijing 100871, China
| | - Beiqi Sun
- College of Engineering, Peking University, Beijing 100871, China
| | - Lei Zhang
- College of Engineering, Peking University, Beijing 100871, China
| | - Fanyang Mo
- School of Materials Science and Engineering, Peking University, Beijing 100871, China
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25
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Dutta S, Kim JH, Bhatt K, Rickertsen DRL, Abboud KA, Ghiviriga I, Seidel D. Alicyclic-Amine-Derived Imine-BF 3 Complexes: Easy-to-Make Building Blocks for the Synthesis of Valuable α-Functionalized Azacycles. Angew Chem Int Ed Engl 2024; 63:e202313247. [PMID: 37909921 PMCID: PMC10835740 DOI: 10.1002/anie.202313247] [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: 09/06/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/03/2023]
Abstract
A new strategy to access α-functionalized alicyclic amines via their corresponding imine-BF3 complexes is reported. Isolable imine-BF3 complexes, readily prepared via dehydrohalogenation of N-bromoamines in a base-promoted/18-crown-6 catalyzed process followed by addition of boron trifluoride etherate, undergo reactions with a wide range of organometallic nucleophiles to afford α-functionalized azacycles. Organozinc and organomagnesium nucleophiles add at ambient temperatures, obviating the need for cryogenic conditions. In situ preparation of imine-BF3 complexes provides access to α-functionalized morpholines and piperazines directly from their parent amines in a single operation. α-Functionalized morpholines can be elaborated further, for instance by installing a second substituent in the α'-position.
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Affiliation(s)
- Subhradeep Dutta
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Jae Hyun Kim
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Kamal Bhatt
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Dillon R L Rickertsen
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
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26
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Mukherjee S, Mondal S, Ghosh P. O 2 Activation by a Coordinated -NH- Function: Hydrogen Atom Transfer and Aromatic Ring Oxidation. Inorg Chem 2023; 62:21147-21155. [PMID: 38047920 DOI: 10.1021/acs.inorgchem.3c03038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Herein, we disclose a unique method of oxidation of a 1,4-naphthoquinone ring in air. We report that (1,4-naphthoquinone)-NH-N=C(OH)Ph (H3L) coordinated to octahedral ruthenium(II) and osmium(II) ions activates an 3O2 molecule spontaneously. Hydrogen atom transfer (HAT) from the -NH- function of H3L to 3O2 and subsequent (2e + 2H+) oxidation forming (1,3,4-trioxonaphthalen)=N-N=C(OH)Ph (HLOX) have been established. The H3L → HLOX transformation occurs via (3-hydroperoxy-1,4-naphthoquinone)=N-N=C(O-)Ph (HLOOH-) as an intermediate. The primary step is HAT generating H2L•- and hydroperoxide (OOH•) radicals. H2L•- is delocalized over the aromatic ring and incites coupling reactions via ortho carbon and produces coordinated HLOOH-. In solution, the homolytic cleavage of the peroxo bond leads to aromatic ring oxidation, affording LOX-. Ruthenium(II) and osmium(II) complexes of the types [MII(H2L-)(PPh3)2X], [MII(HLOOH-)(PPh3)2X], and trans-[MII(LOX-)(PPh3)2X] were successfully isolated in good yields. Notably, the cyclic voltammograms of all of the complexes exhibit reversible anodic waves due to MIII/MII redox couples. The rate constants of the [MII(H2L-)(PPh3)2X] → [MII(HLOOH-)(PPh3)2X] conversions determined by time-driven UV-vis spectroscopy in dry CH2Cl2, wet CH2Cl2, and D2O wet CH2Cl2 in air at 298 K follow the order k CH 2 Cl 2 -H 2 O > k CH 2 Cl 2 -D 2 O > k CH 2 Cl 2 . It is established that the rate constants are dependent on the 3O2 content of the solution but not on the concentration of the complex.
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Affiliation(s)
- Souvik Mukherjee
- Department of Chemistry, Ramakrishna Mission Residential College (Autonomous), Narendrapur, Kolkata 700 103, India
| | - Sandip Mondal
- Department of Chemistry, Darjeeling Government College, Darjeeling 734101, WB, India
| | - Prasanta Ghosh
- Department of Chemistry, Ramakrishna Mission Residential College (Autonomous), Narendrapur, Kolkata 700 103, India
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27
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Wu Y, Zhang W, Ma S, Song C, Chang J. Copper-Catalyzed Synthesis of N-Fused Quinolines via C(sp 3)-H Activation-Radical Addition-Cyclization Cascade. J Org Chem 2023. [PMID: 38012068 DOI: 10.1021/acs.joc.3c01812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
A novel copper-catalyzed cyclization reaction for the synthesis of pyrazolo[1,5-a]quinoline, triazolo[1,5-a]quinoline, and pyrrolo[1,2-a]quinoline derivatives is described. The process is initiated by di-tert-butyl peroxide-mediated C(sp3)-H activation to generate the α-functionalized radical, which supervenes a cascade radical addition/cyclization sequence to access the N-fused quinolines in good yields with broad functional group tolerance.
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Affiliation(s)
- Yangang Wu
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
| | - Wen Zhang
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
| | - Shiyu Ma
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
| | - Chuanjun Song
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
| | - Junbiao Chang
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
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28
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de Jesus R, Hiesinger K, van Gemmeren M. Preparative Scale Applications of C-H Activation in Medicinal Chemistry. Angew Chem Int Ed Engl 2023; 62:e202306659. [PMID: 37283078 DOI: 10.1002/anie.202306659] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/08/2023]
Abstract
C-H activation is an attractive methodology to increase molecular complexity without requiring substrate prefunctionalization. In contrast to well-established cross-coupling methods, C-H activation is less explored on large scales and its use in the production of pharmaceuticals faces substantial hurdles. However, the inherent advantages, such as shorter synthetic routes and simpler starting materials, motivate medicinal chemists and process chemists to overcome these challenges, and exploit C-H activation steps for the synthesis of pharmaceutically relevant compounds. In this review, we will cover examples of drugs/drug candidates where C-H activation has been implemented on a preparative synthetic scale (range between 355 mg and 130 kg). The optimization processes will be described, and each example will be examined in terms of its advantages and disadvantages, providing the reader with an in-depth understanding of the challenges and potential of C-H activation methodologies in the production of pharmaceuticals.
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Affiliation(s)
- Rita de Jesus
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Kerstin Hiesinger
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Manuel van Gemmeren
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
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29
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Yue WJ, Martin R. α-Difluoroalkylation of Benzyl Amines with Trifluoromethylarenes. Angew Chem Int Ed Engl 2023; 62:e202310304. [PMID: 37596243 DOI: 10.1002/anie.202310304] [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: 07/19/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/20/2023]
Abstract
An α-difluoroalkylation of benzyl amines with trifluoromethylarenes is disclosed herein. This protocol is characterized by its operational simplicity, excellent chemoselectivity and broad scope-even with advanced synthetic intermediates-, thus offering a new entry point to medicinally-relevant α-difluoroalkylated amines from simple, yet readily accessible, precursors.
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Affiliation(s)
- Wen-Jun Yue
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
- Universitat Rovira i Virgili, Departament de Química Analítica i Química Orgànica, c/Marcel⋅lí Domingo, 1, 43007, Tarragona, Spain
| | - Ruben Martin
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluïs Companys, 23, 08010, Barcelona, Spain
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30
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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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31
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Meger FS, Murphy JA. Recent Advances in C-H Functionalisation through Indirect Hydrogen Atom Transfer. Molecules 2023; 28:6127. [PMID: 37630379 PMCID: PMC10459052 DOI: 10.3390/molecules28166127] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/09/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
The functionalisation of C-H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple synthetic equivalents for synthons. Hydrogen atom transfer (HAT) is a key method for forming alkyl radicals from C-H substrates. Classic reactions, including the Barton nitrite ester reaction and Hofmann-Löffler-Freytag reaction, among others, provided early examples of HAT. However, recent developments in photoredox catalysis and electrochemistry have made HAT a powerful synthetic tool capable of introducing a wide range of functional groups into C-H bonds. Moreover, greater mechanistic insights into HAT have stimulated the development of increasingly site-selective protocols. Site-selectivity can be achieved through the tuning of electron density at certain C-H bonds using additives, a judicious choice of HAT reagent, and a solvent system. Herein, we describe the latest methods for functionalizing C-H/Si-H/Ge-H bonds using indirect HAT between 2018-2023, as well as a critical discussion of new HAT reagents, mechanistic aspects, substrate scopes, and background contexts of the protocols.
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Affiliation(s)
- Filip S. Meger
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, 16 Avinguda dels Països Catalans, 43007 Tarragona, Catalonia, Spain
| | - John A. Murphy
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
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32
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Call A, Capocasa G, Palone A, Vicens L, Aparicio E, Choukairi Afailal N, Siakavaras N, López Saló ME, Bietti M, Costas M. Highly Enantioselective Catalytic Lactonization at Nonactivated Primary and Secondary γ-C-H Bonds. J Am Chem Soc 2023; 145:18094-18103. [PMID: 37540636 PMCID: PMC10507665 DOI: 10.1021/jacs.3c06231] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Indexed: 08/06/2023]
Abstract
Chiral oxygenated aliphatic moieties are recurrent in biological and pharmaceutically relevant molecules and constitute one of the most versatile types of functionalities for further elaboration. Herein we report a protocol for straightforward and general access to chiral γ-lactones via enantioselective oxidation of strong nonactivated primary and secondary C(sp3)-H bonds in readily available carboxylic acids. The key enabling aspect is the use of robust sterically encumbered manganese catalysts that provide outstanding enantioselectivities (up to >99.9%) and yields (up to 96%) employing hydrogen peroxide as the oxidant. The resulting γ-lactones are of immediate interest for the preparation of inter alia natural products and recyclable polymeric materials.
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Affiliation(s)
- Arnau Call
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Giorgio Capocasa
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Andrea Palone
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Laia Vicens
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Eric Aparicio
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Najoua Choukairi Afailal
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Nikos Siakavaras
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Maria Eugènia López Saló
- Institut
de Química Computacional i Catàlisi (IQCC) and 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) and Departament
de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
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33
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Dutta S, Bhatt K, Cuffel F, Seidel D. Synthesis of Polycyclic Imidazoles via α-C-H/N-H Annulation of Alicyclic Amines. SYNTHESIS-STUTTGART 2023; 55:2343-2352. [PMID: 38314182 PMCID: PMC10836336 DOI: 10.1055/a-2022-1511] [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: 02/01/2023]
Abstract
Secondary alicyclic amines are converted to their corresponding ring-fused imidazoles in a simple procedure consisting of oxidative imine formation followed by a van Leusen reaction. Amines with an existing α-substituent undergo regioselective ring-fusion at the α'-position. This method was utilized in a synthesis of fadrozole.
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Affiliation(s)
- Subhradeep Dutta
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Kamal Bhatt
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Fabian Cuffel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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34
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Lepori M, Schmid S, Barham JP. Photoredox catalysis harvesting multiple photon or electrochemical energies. Beilstein J Org Chem 2023; 19:1055-1145. [PMID: 37533877 PMCID: PMC10390843 DOI: 10.3762/bjoc.19.81] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/07/2023] [Indexed: 08/04/2023] Open
Abstract
Photoredox catalysis (PRC) is a cutting-edge frontier for single electron-transfer (SET) reactions, enabling the generation of reactive intermediates for both oxidative and reductive processes via photon activation of a catalyst. Although this represents a significant step towards chemoselective and, more generally, sustainable chemistry, its efficacy is limited by the energy of visible light photons. Nowadays, excellent alternative conditions are available to overcome these limitations, harvesting two different but correlated concepts: the use of multi-photon processes such as consecutive photoinduced electron transfer (conPET) and the combination of photo- and electrochemistry in synthetic photoelectrochemistry (PEC). Herein, we review the most recent contributions to these fields in both oxidative and reductive activations of organic functional groups. New opportunities for organic chemists are captured, such as selective reactions employing super-oxidants and super-reductants to engage unactivated chemical feedstocks, and scalability up to gram scales in continuous flow. This review provides comparisons between the two techniques (multi-photon photoredox catalysis and PEC) to help the reader to fully understand their similarities, differences and potential applications and to therefore choose which method is the most appropriate for a given reaction, scale and purpose of a project.
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Affiliation(s)
- Mattia Lepori
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
| | - Simon Schmid
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
| | - Joshua P Barham
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
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35
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Salameh N, Valentini F, Baudoin O, Vaccaro L. A General Enantioselective C-H Arylation Using an Immobilized Recoverable Palladium Catalyst. CHEMSUSCHEM 2023:e202300609. [PMID: 37486306 DOI: 10.1002/cssc.202300609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/11/2023] [Accepted: 07/24/2023] [Indexed: 07/25/2023]
Abstract
We herein report a general and efficient enantioselective C-H arylation of aryl bromides based on the use of BozPhos as the bisphosphine ligand and SP-NHC-PdII as recoverable heterogeneous catalyst. By exploiting the "release and catch" mechanism of action of the catalytic system, we used BozPhos as a broadly applicable chiral ligand, furnishing high enantioselectivities across all types of examined substrates containing methyl, cyclopropyl and aryl C-H bonds. For each reaction, the reaction scope was investigated, giving rise to 30 enantioenriched products, obtained with high yields and enantioselectivities, and minimal palladium leaching. The developed catalytic system provides a more sustainable solution compared to homogeneous systems for the synthesis of high added-value chiral products through recycling of the precious metal.
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Affiliation(s)
- Nihad Salameh
- Laboratory of Green SOC, Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Via Elce di Sotto, 8, 06124, Perugia, Italy
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056, Basel, Switzerland
| | - Federica Valentini
- Laboratory of Green SOC, Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Via Elce di Sotto, 8, 06124, Perugia, Italy
| | - Olivier Baudoin
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056, Basel, Switzerland
| | - Luigi Vaccaro
- Laboratory of Green SOC, Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Via Elce di Sotto, 8, 06124, Perugia, Italy
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36
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Chang L, Wang S, An Q, Liu L, Wang H, Li Y, Feng K, Zuo Z. Resurgence and advancement of photochemical hydrogen atom transfer processes in selective alkane functionalizations. Chem Sci 2023; 14:6841-6859. [PMID: 37389263 PMCID: PMC10306100 DOI: 10.1039/d3sc01118f] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 05/11/2023] [Indexed: 07/01/2023] Open
Abstract
The selective functionalization of alkanes has long been recognized as a prominent challenge and an arduous task in organic synthesis. Hydrogen atom transfer (HAT) processes enable the direct generation of reactive alkyl radicals from feedstock alkanes and have been successfully employed in industrial applications such as the methane chlorination process, etc. Nevertheless, challenges in the regulation of radical generation and reaction pathways have created substantial obstacles in the development of diversified alkane functionalizations. In recent years, the application of photoredox catalysis has provided exciting opportunities for alkane C-H functionalization under extremely mild conditions to trigger HAT processes and achieve radical-mediated functionalizations in a more selective manner. Considerable efforts have been devoted to building more efficient and cost-effective photocatalytic systems for sustainable transformations. In this perspective, we highlight the recent development of photocatalytic systems and provide our views on current challenges and future opportunities in this field.
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Affiliation(s)
- Liang Chang
- School of Pharmacy, Nanjing University of Chinese Medicine Nanjing 210023 China
| | - Shun Wang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Qing An
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Linxuan Liu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Hexiang Wang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Yubo Li
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Kaixuan Feng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
| | - Zhiwei Zuo
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 China
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37
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Sneha M, Thornton GL, Lewis-Borrell L, Ryder ASH, Espley SG, Clark IP, Cresswell AJ, Grayson MN, Orr-Ewing AJ. Photoredox-HAT Catalysis for Primary Amine α-C-H Alkylation: Mechanistic Insight with Transient Absorption Spectroscopy. ACS Catal 2023; 13:8004-8013. [PMID: 37342833 PMCID: PMC10278065 DOI: 10.1021/acscatal.3c01474] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/17/2023] [Indexed: 06/23/2023]
Abstract
The synergistic use of (organo)photoredox catalysts with hydrogen-atom transfer (HAT) cocatalysts has emerged as a powerful strategy for innate C(sp3)-H bond functionalization, particularly for C-H bonds α- to nitrogen. Azide ion (N3-) was recently identified as an effective HAT catalyst for the challenging α-C-H alkylation of unprotected, primary alkylamines, in combination with dicyanoarene photocatalysts such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN). Here, time-resolved transient absorption spectroscopy over sub-picosecond to microsecond timescales provides kinetic and mechanistic details of the photoredox catalytic cycle in acetonitrile solution. Direct observation of the electron transfer from N3- to photoexcited 4CzIPN reveals the participation of the S1 excited electronic state of the organic photocatalyst as an electron acceptor, but the N3• radical product of this reaction is not observed. Instead, both time-resolved infrared and UV-visible spectroscopic measurements implicate rapid association of N3• with N3- (a favorable process in acetonitrile) to form the N6•- radical anion. Electronic structure calculations indicate that N3• is the active participant in the HAT reaction, suggesting a role for N6•- as a reservoir that regulates the concentration of N3•.
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Affiliation(s)
- Mahima Sneha
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- Department
of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Georgia L. Thornton
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Luke Lewis-Borrell
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Alison S. H. Ryder
- Centre
for Sustainable Chemical Technologies, University
of Bath, 1 South, Claverton Down, Bath BA2 7AY, U.K.
| | - Samuel G. Espley
- Department
of Chemistry, University of Bath, 1 South, Claverton Down, Bath BA2 7AY, U.K.
| | - Ian P. Clark
- Central
Laser Facility, Research Complex at Harwell, Science and Technology
Facilities Council, Rutherford Appleton
Laboratory, Harwell Oxford, Didcot OX11 0QX, U.K.
| | - Alexander J. Cresswell
- Department
of Chemistry, University of Bath, 1 South, Claverton Down, Bath BA2 7AY, U.K.
| | - Matthew N. Grayson
- Department
of Chemistry, University of Bath, 1 South, Claverton Down, Bath BA2 7AY, U.K.
| | - Andrew J. Orr-Ewing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
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38
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van den Heuvel N, Mason SM, Mercado BQ, Miller SJ. Aspartyl β-Turn-Based Dirhodium(II) Metallopeptides for Benzylic C(sp 3)-H Amination: Enantioselectivity and X-ray Structural Analysis. J Am Chem Soc 2023; 145:12377-12385. [PMID: 37216431 PMCID: PMC10330621 DOI: 10.1021/jacs.3c03587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Amination of C(sp3)-H bonds is a powerful tool to introduce nitrogen into complex organic frameworks in a direct manner. Despite significant advances in catalyst design, full site- and enantiocontrol in complex molecular regimes remain elusive using established catalyst systems. To address these challenges, we herein describe a new class of peptide-based dirhodium(II) complexes derived from aspartic acid-containing β-turn-forming tetramers. This highly modular system can serve as a platform for the rapid generation of new chiral dirhodium(II) catalyst libraries, as illustrated by the facile synthesis of a series of 38 catalysts. Critically, we present the first crystal structure of a dirhodium(II) tetra-aspartate complex, which unveils retention of the β-turn conformation of the peptidyl ligand; a well-defined hydrogen-bonding network is evident, along with a near-C4 symmetry that renders the rhodium centers inequivalent. The utility of this catalyst platform is illustrated by the enantioselective amination of benzylic C(sp3)-H bonds, in which state-of-the-art levels of enantioselectivity up to 95.5:4.5 er are obtained, even for substrates that present challenges with previously reported catalyst systems. Additionally, we found these complexes to be competent catalysts for the intermolecular amination of N-alkylamides via insertion into the C(sp3)-H bond α to the amide nitrogen, yielding differentially protected 1,1-diamines. Of note, this type of insertion was also observed to occur on the amide functionalities of the catalyst itself in the absence of the substrate but did not appear to be detrimental to reaction outcomes when the substrate was present.
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Affiliation(s)
- Naudin van den Heuvel
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Savannah M. Mason
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Brandon Q. Mercado
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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39
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Peng P, Zhong Y, Zhou C, Tao Y, Li D, Lu Q. Unlocking the Nucleophilicity of Strong Alkyl C-H Bonds via Cu/Cr Catalysis. ACS CENTRAL SCIENCE 2023; 9:756-762. [PMID: 37122460 PMCID: PMC10141608 DOI: 10.1021/acscentsci.2c01389] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Indexed: 05/03/2023]
Abstract
Direct functionalization of inert C-H bonds is one of the most attractive yet challenging strategies for constructing molecules in organic chemistry. Herein, we disclose an unprecedented and Earth abundant Cu/Cr catalytic system in which unreactive alkyl C-H bonds are transformed into nucleophilic alkyl-Cr(III) species at room temperature, enabling carbonyl addition reactions with strong alkyl C-H bonds. Various aryl alkyl alcohols are furnished under mild reaction conditions even on a gram scale. Moreover, this new radical-to-polar crossover approach is further applied to the 1,1-difunctionalization of aldehydes with alkanes and different nucleophiles. Mechanistic investigations reveal that the aldehyde not only acts as a reactant but also serves as a photosensitizer to recycle the Cu and Cr catalysts.
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Affiliation(s)
- Pan Peng
- The
Institute for Advanced Studies (IAS), Wuhan
University, Wuhan 430072, P. R. China
| | - Yifan Zhong
- The
Institute for Advanced Studies (IAS), Wuhan
University, Wuhan 430072, P. R. China
| | - Cong Zhou
- The
Institute for Advanced Studies (IAS), Wuhan
University, Wuhan 430072, P. R. China
| | - Yongsheng Tao
- The
Institute for Advanced Studies (IAS), Wuhan
University, Wuhan 430072, P. R. China
| | - Dandan Li
- Key
Laboratory of Micro-Nano Materials for Energy Storage and Conversion
of Henan Province, Institute of Surface Micro and Nano Materials,
College of Chemical and Materials Engineering, Xuchang University, Henan 461000, P. R. China
| | - Qingquan Lu
- The
Institute for Advanced Studies (IAS), Wuhan
University, Wuhan 430072, P. R. China
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40
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Yan SB, Wang R, Li ZG, Li AN, Wang C, Duan WL. Copper-catalyzed asymmetric C(sp 2)-H arylation for the synthesis of P- and axially chiral phosphorus compounds. Nat Commun 2023; 14:2264. [PMID: 37081007 PMCID: PMC10119316 DOI: 10.1038/s41467-023-37987-8] [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: 10/11/2022] [Accepted: 04/04/2023] [Indexed: 04/22/2023] Open
Abstract
Transition metal-catalyzed C-H bond functionalization is an important method in organic synthesis, but the development of methods that are lower cost and have a less environmental impact is desirable. Here, a Cu-catalyzed asymmetric C(sp2)-H arylation is reported. With diaryliodonium salts as arylating reagents, a range of ortho-arylated P-chiral phosphonic diamides were obtained in moderate to excellent yields with high enantioselectivities (up to 92% ee). Meanwhile, enantioselective C-3 arylation of diarylphosphine oxide indoles was also realized under similar conditions to construct axial chirality.
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Affiliation(s)
- Shao-Bai Yan
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China
| | - Rui Wang
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China
| | - Zha-Gen Li
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China
| | - An-Na Li
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China
| | - Chuanyong Wang
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China
| | - Wei-Liang Duan
- College of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Road, 225002, Yangzhou, China.
- College of Chemistry and Chemical Engineering, Inner Mongolia University, 235 West University Street, 010021, Hohhot, China.
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 Xi Changan Street, 710119, Xi'an, China.
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41
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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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42
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Sihag P, Chakraborty T, Jeganmohan M. Rhodium-Catalyzed Allylic C-H Functionalization of Unactivated Alkenes with α-Diazocarbonyl Compounds. Org Lett 2023. [PMID: 36795960 DOI: 10.1021/acs.orglett.2c04356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
A redox-neutral mild methodology for the allylic C-H alkylation of unactivated alkenes with diazo compounds is demonstrated. The developed protocol is able to bypass the possibility of the cyclopropanation of an alkene upon its reaction with the acceptor-acceptor diazo compounds. The protocol is highly accomplished due to its compatibility with various unactivated alkenes functionalized with different sensitive functional groups. A rhodacycle π-allyl intermediate has been synthesized and proved to be the active intermediate. Additional mechanistic investigations aided the elucidation of the plausible reaction mechanism.
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Affiliation(s)
- Pinki Sihag
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Trisha Chakraborty
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Masilamani Jeganmohan
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
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43
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Das M, Zamani L, Bratcher C, Musacchio PZ. Azolation of Benzylic C-H Bonds via Photoredox-Catalyzed Carbocation Generation. J Am Chem Soc 2023; 145:10.1021/jacs.2c12850. [PMID: 36757817 PMCID: PMC10409882 DOI: 10.1021/jacs.2c12850] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
A visible-light photoredox-catalyzed method is reported that enables the coupling between benzylic C-H substrates and N-H azoles. Classically, medicinally relevant N-benzyl azoles are produced via harsh substitution conditions between the azole and a benzyl electrophile in the presence of strong bases at high temperatures. Use of C-H bonds as the alkylating partner streamlines the preparation of these important motifs. In this work, we report the use of N-alkoxypyridinium salts as a critically enabling reagent for the development of a general C(sp3)-H azolation. The platform enables the alkylation of electron-deficient, -neutral, and -rich azoles with a range of C-H bonds, most notably secondary and tertiary partners. Moreover, the protocol is mild enough to tolerate benzyl electrophiles, thus offering an orthogonal approach to existing SN2 and cross-coupling methods.
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Affiliation(s)
- Mrinmoy Das
- Department of Chemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
| | - Leila Zamani
- Department of Chemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
| | - Christopher Bratcher
- Department of Chemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
| | - Patricia Z Musacchio
- Department of Chemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
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44
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Sukiennik J, Pranowo A, Domański S, Hurej K. Manganese(III) porphyrin-catalyzed regioselective dual functionalization of C(sp 3)-H bonds: the transformation of arylalkanes to 1,4-diketones. Chem Commun (Camb) 2023; 59:1149-1152. [PMID: 36594254 DOI: 10.1039/d2cc06126k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The first, direct way from arylalkanes to 1,4-dicarbonyl compounds has been shown. It makes obtaining these useful products more accessible and cheaper. Our method is based on a one-pot reaction with excellent regioselectivity, mild conditions, and water as the main solvent. A plausible reaction mechanism has also been proposed.
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Affiliation(s)
- Jakub Sukiennik
- Department of Chemistry, University of Wroclaw, F. Joliot-Curie 14, Wrocław 50383, Poland.
| | - Audrey Pranowo
- Department of Chemistry, University of Wroclaw, F. Joliot-Curie 14, Wrocław 50383, Poland.
| | | | - Karolina Hurej
- Department of Chemistry, University of Wroclaw, F. Joliot-Curie 14, Wrocław 50383, Poland.
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45
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Desai B, Uppuluru A, Dey A, Deshpande N, Dholakiya BZ, Sivaramakrishna A, Naveen T, Padala K. The recent advances in cobalt-catalyzed C(sp 3)-H functionalization reactions. Org Biomol Chem 2023; 21:673-699. [PMID: 36602117 DOI: 10.1039/d2ob01936a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Over the past decades, reactions involving C-H functionalization have become a hot theme in organic transformations because they have a lot of potential for the streamlined synthesis of complex molecules. C(sp3)-H bonds are present in most organic species. Since organic molecules have massive significance in various aspects of life, the exploitation and functionalization of C(sp3)-H bonds hold enormous importance. In recent years, the first-row transition metal-catalyzed direct and selective functionalization of C-H bonds has emerged as a simple and environmentally friendly synthetic method due to its low cost, unique reactivity profiles and easy availability. Therefore, research advancements are being made to conceive catalytic systems that foster direct C(sp3)-H functionalization under benign reaction conditions. Cobalt-based catalysts offer mild and convenient reaction conditions at a reasonable expense compared to conventional 2nd and 3rd-row transition metal catalysts. Consequently, the probing of Co-based catalysts for C(sp3)-H functionalization is one of the hot topics from the outlook of an organic chemist. This review primarily focuses on the literature from 2018 to 2022 and sheds light on the substrate scope, selectivity, benefits and limitations of cobalt catalysts for organic transformations.
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Affiliation(s)
- Bhargav Desai
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat-395 007, India.
| | - Ajay Uppuluru
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Katpadi, Vellore, Tamil Nadu, 632014, India.
| | - Ashutosh Dey
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Katpadi, Vellore, Tamil Nadu, 632014, India.
| | - Neha Deshpande
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat-395 007, India.
| | - Bharatkumar Z Dholakiya
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat-395 007, India.
| | - Akella Sivaramakrishna
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Katpadi, Vellore, Tamil Nadu, 632014, India.
| | - Togati Naveen
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat-395 007, India.
| | - Kishor Padala
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Katpadi, Vellore, Tamil Nadu, 632014, India. .,Central Tribal University of Andhra Pradesh, Kondakarakam Village, Cantonment, Vizianagaram, Andhra Pradesh, 535003, India
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46
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Maayuri R, Gandeepan P. Manganese-catalyzed hydroarylation of multiple bonds. Org Biomol Chem 2023; 21:441-464. [PMID: 36541044 DOI: 10.1039/d2ob01674e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transition metal-catalyzed C-H activation has become a promising strategy in organic synthesis due to its improved atom-, step- and resource economy. Considering the Earth's abundance, economic benefits, and low toxicity, 3d metal catalysts for C-H activation have received a significant focus. In particular, organometallic manganese-catalyzed C-H activation has proven to be versatile and suitable for a wide range of transformations such as C-H addition to π-components, arylation, alkylation, alkynylation, amination, and many more. Among them, manganese-catalyzed C-H addition to C-C and C-heteroatom multiple bonds exhibited unique and promising reactivity to construct a wide range of complex organic molecules. In this review, we highlight the developments in the field of manganese-catalyzed hydroarylation of multiple bonds via C-H activation with a range of applications until August 2022.
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Affiliation(s)
- Rajaram Maayuri
- Department of Chemistry, Indian Institute of Technology Tirupati, Yerpedu-Venkatagiri Road, Yerpedu Post, Tirupati District, Andhra Pradesh 517619, India.
| | - Parthasarathy Gandeepan
- Department of Chemistry, Indian Institute of Technology Tirupati, Yerpedu-Venkatagiri Road, Yerpedu Post, Tirupati District, Andhra Pradesh 517619, India.
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47
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Papadopoulou A, Meyer F, Buller RM. Engineering Fe(II)/α-Ketoglutarate-Dependent Halogenases and Desaturases. Biochemistry 2023; 62:229-240. [PMID: 35446547 DOI: 10.1021/acs.biochem.2c00115] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Fe(II)/α-ketoglutarate-dependent dioxygenases (α-KGDs) are widespread enzymes in aerobic biology and serve a remarkable array of biological functions, including roles in collagen biosynthesis, plant and animal development, transcriptional regulation, nucleic acid modification, and secondary metabolite biosynthesis. This functional diversity is reflected in the enzymes' catalytic flexibility as α-KGDs can catalyze an intriguing set of synthetically valuable reactions, such as hydroxylations, halogenations, and desaturations, capturing the interest of scientists across disciplines. Mechanistically, all α-KGDs are understood to follow a similar activation pathway to generate a substrate radical, yet how individual members of the enzyme family direct this key intermediate toward the different reaction outcomes remains elusive, triggering structural, computational, spectroscopic, kinetic, and enzyme engineering studies. In this Perspective, we will highlight how first enzyme and substrate engineering examples suggest that the chemical reaction pathway within α-KGDs can be intentionally tailored using rational design principles. We will delineate the structural and mechanistic investigations of the reprogrammed enzymes and how they begin to inform about the enzymes' structure-function relationships that determine chemoselectivity. Application of this knowledge in future enzyme and substrate engineering campaigns will lead to the development of powerful C-H activation catalysts for chemical synthesis.
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Affiliation(s)
- Athena Papadopoulou
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland
| | - Fabian Meyer
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland
| | - Rebecca M Buller
- Competence Center for Biocatalysis, Zurich University of Applied Sciences, Einsiedlerstrasse 31, 8820 Wädenswil, Switzerland
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48
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Greiner LC, Arichi N, Inuki S, Ohno H. Gold(I)-Catalyzed Benzylic C(sp 3 )-H Functionalizations: Divergent Synthesis of Indole[a]- and [b]-Fused Polycycles. Angew Chem Int Ed Engl 2023; 62:e202213653. [PMID: 36255174 DOI: 10.1002/anie.202213653] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/17/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Phenyl azides substituted by an (alkylphenyl)ethynyl group facilitate benzylic sp3 (C-H) functionalization in the presence of a JohnPhosAu catalyst, resulting in indole-fused tetra- and pentacycles via divergent N- or C-cyclization. The chemoselectivity is influenced depending on the counter-anion, the electron density of the α-imino gold(I) carbene, and the alkyl groups stabilizing the benzylic carbocation originating from a 1,5-hydride shift. An isotopic labeling experiment demonstrates the involvement of an indolylgold(I) species resulting from a tautomerization that is much faster than the deauration. The formation of a benzylic sp3 (C-H) functionalization leading to an indole-fused seven-membered ring is also demonstrated.
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Affiliation(s)
- Luca C Greiner
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Norihito Arichi
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
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49
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An Q, Xing YY, Pu R, Jia M, Chen Y, Hu A, Zhang SQ, Yu N, Du J, Zhang Y, Chen J, Liu W, Hong X, Zuo Z. Identification of Alkoxy Radicals as Hydrogen Atom Transfer Agents in Ce-Catalyzed C-H Functionalization. J Am Chem Soc 2023; 145:359-376. [PMID: 36538367 DOI: 10.1021/jacs.2c10126] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The intermediacy of alkoxy radicals in cerium-catalyzed C-H functionalization via H-atom abstraction has been unambiguously confirmed. Catalytically relevant Ce(IV)-alkoxide complexes have been synthesized and characterized by X-ray diffraction. Operando electron paramagnetic resonance and transient absorption spectroscopy experiments on isolated pentachloro Ce(IV) alkoxides identified alkoxy radicals as the sole heteroatom-centered radical species generated via ligand-to-metal charge transfer (LMCT) excitation. Alkoxy-radical-mediated hydrogen atom transfer (HAT) has been verified via kinetic analysis, density functional theory (DFT) calculations, and reactions under strictly chloride-free conditions. These experimental findings unambiguously establish the critical role of alkoxy radicals in Ce-LMCT catalysis and definitively preclude the involvement of chlorine radical. This study has also reinforced the necessity of a high relative ratio of alcohol vs Ce for the selective alkoxy-radical-mediated HAT, as seemingly trivial changes in the relative ratio of alcohol vs Ce can lead to drastically different mechanistic pathways. Importantly, the previously proposed chlorine radical-alcohol complex, postulated to explain alkoxy-radical-enabled selectivities in this system, has been examined under scrutiny and ruled out by regioselectivity studies, transient absorption experiments, and high-level calculations. Moreover, the peculiar selectivity of alkoxy radical generation in the LMCT homolysis of Ce(IV) heteroleptic complexes has been analyzed and back-electron transfer (BET) may have regulated the efficiency and selectivity for the formation of ligand-centered radicals.
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Affiliation(s)
- Qing An
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yang-Yang Xing
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310007, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Ruihua Pu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Menghui Jia
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yuegang Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Anhua Hu
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Shuo-Qing Zhang
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310007, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Na Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jianbo Du
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yanxia Zhang
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xin Hong
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310007, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street NO. 2, Beijing 100190, China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Zhiwei Zuo
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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Vorobyeva DV, Bubnova AS, Buyanovskaya AG, Osipov SN. Synthesis of CF3-substituted isoindolones via rhodium(iii)-catalyzed carbenoid C–H functionalization of aryl hydroxamates. MENDELEEV COMMUNICATIONS 2023. [DOI: 10.1016/j.mencom.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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