1
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Chen J, Tan C, Rodrigalvarez J, Zhang S, Martin R. Site-Selective Distal C(sp 3)-H Bromination of Aliphatic Amines as a Gateway for Forging Nitrogen-Containing sp 3 Architectures. Angew Chem Int Ed Engl 2024; 63:e202406485. [PMID: 38770612 DOI: 10.1002/anie.202406485] [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: 04/05/2024] [Revised: 05/03/2024] [Accepted: 05/20/2024] [Indexed: 05/22/2024]
Abstract
Herein, we disclose a new strategy that rapidly and reliably incorporates bromine atoms at distal, secondary C(sp3)-H sites in aliphatic amines with an excellent and predictable site-selectivity pattern. The resulting halogenated building blocks serve as versatile linchpins to enable a series of carbon-carbon and carbon-heteroatom bond-formations at remote C(sp3) sites, thus offering a new modular and unified platform that expediates the access to advanced sp3 architectures possessing valuable nitrogen-containing saturated heterocycles of interest in medicinal chemistry settings.
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Affiliation(s)
- Jinhong Chen
- 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
| | - Clarence Tan
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
| | - Jesus Rodrigalvarez
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Països Catalans 16, 43007, Tarragona, Spain
| | - Shuai Zhang
- 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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2
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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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3
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Lasky MR, Liu EC, Remy MS, Sanford MS. Visible-Light Photocatalytic C-H Amination of Arenes Utilizing Acridine-Lewis Acid Complexes. J Am Chem Soc 2024; 146:14799-14806. [PMID: 38759094 DOI: 10.1021/jacs.4c02991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024]
Abstract
This report describes the development of a visible-light photocatalytic system for C(sp2)-H amination that leverages in situ-generated photocatalysts. We demonstrate that the combination of acridine derivatives and Lewis acids forms potent photooxidants that promote the C-H amination of electronically diverse arenes upon irradiation with visible-light (440 nm). A first-generation photocatalyst composed of Sc(OTf)3 and acridine effects the C-H amination of substrates with oxidation potentials ≤ +2.5 V vs SCE with pyrazole, triazole, and pyridine nucleophiles. Furthermore, the simplicity and modularity of this system enable variation of both Lewis acid and acridine to tune reactivity. This enabled the rapid identification of two second-generation photocatalysts (derived from (i) Al(OTf)3 and acridine or (ii) Sc(OTf)3 and a pyridinium-substituted acridine) that catalyze a particularly challenging transformation: C(sp2)-H amination with benzene as the limiting reagent.
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Affiliation(s)
- Matthew R Lasky
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - En-Chih Liu
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Matthew S Remy
- Corporate R&D, Dow, 1776 Building, Midland, Michigan 48667, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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4
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Golden DL, Flynn KM, Aikonen S, Hanneman CM, Kalyani D, Krska SW, Paton RS, Stahl SS. Radical Chlorination of Non-Resonant Heterobenzylic C-H Bonds and High-Throughput Diversification of Heterocycles. Chem 2024; 10:1593-1605. [PMID: 39108591 PMCID: PMC11299866 DOI: 10.1016/j.chempr.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Site-selective functionalization of the heterobenzylic C(sp3)-H bonds of pyridines and related heteroaromatic compounds presents challenges associated with the basic nitrogen atom and the variable reactivity among different positions on the heteroaromatic ring. Methods for functionalization of 2- and 4-alkylpyridines are increasingly available through polar pathways that leverage resonance stabilization of charge build-up at these positions. In contrast, functionalization of 3-alkylpyridines is largely inaccessible. Here, we report a photochemically promoted method for chlorination of non-resonant heterobenzylic C(sp3)-H sites in 3-alkylpyridines and related alkylheteroaromatics. Density functional theory calculations show that the optimal reactivity reflects a balance between the energetics of the two radical-chain propagation steps, with the preferred reagent consisting of an N-chlorosulfonamide. The operationally simple chlorination protocol enables access to heterobenzylic chlorides which serve as versatile intermediates in C-H cross-coupling reactions between heteroaromatic building blocks and diverse oxidatively sensitive nucleophiles using high-throughput experimentation.
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Affiliation(s)
- Dung L. Golden
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present address: Chemical Process Development, Bristol Myers Squibb, 556 Morris Avenue, Summit, New Jersey 07901, United States
| | - Kaitlyn M. Flynn
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Present address: Drug Substance Development Chemistry, GSK, 1250 Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Santeri Aikonen
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Ft. Collins, Colorado 80523, United States
- Present address: In Silico Discovery, Johnson & Johnson Innovative Medicine, 1400 McKean Road, Spring House, Pennsylvania 19477, United States
| | - Christopher M. Hanneman
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Dipannita Kalyani
- Discovery Chemistry, Merck & Co., Inc., 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
| | - Shane W. Krska
- Discovery Chemistry, Merck & Co., Inc., 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
| | - Robert S. Paton
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Ft. Collins, Colorado 80523, United States
| | - Shannon S. Stahl
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Lead contact
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5
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Zhang M, Tang ZL, Luo H, Wang XC. β-C-H Allylation of Trialkylamines with Allenes Promoted by Synergistic Borane/Palladium Catalysis. Angew Chem Int Ed Engl 2023:e202317610. [PMID: 38095883 DOI: 10.1002/anie.202317610] [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: 11/19/2023] [Indexed: 12/29/2023]
Abstract
Functionalization of the C(sp3 )-H bonds of trialkylamines is challenging, especially for reactions at positions other than the α position. Herein, we report a method for β-C(sp3 )-H allylation of trialkylamines. In these reactions, which involve synergistic borane/palladium catalysis, an enamine intermediate is first generated from the amine via α,β-dehydrogenation promoted by B(C6 F5 )3 and a base, and then the enamine undergoes palladium-catalyzed reaction with an allene to give the allylation product. Because the hydride and the proton resulting from the initial dehydrogenation are ultimately shuttled to the product by B(C6 F5 )3 and the palladium catalyst, respectively, these reactions show excellent atom economy. The establishment of this method paves the way for future studies of C-H functionalization of trialkylamines by means of synergistic borane/transition-metal catalysis.
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Affiliation(s)
- Ming Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Haihe Laboratory of Sustainable Chemical Transformations, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Zi-Lu Tang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Haihe Laboratory of Sustainable Chemical Transformations, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Heng Luo
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Haihe Laboratory of Sustainable Chemical Transformations, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Xiao-Chen Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Haihe Laboratory of Sustainable Chemical Transformations, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
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6
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Sisti S, Galeotti M, Scarchilli F, Salamone M, Costas M, Bietti M. Highly Selective C(sp 3)-H Bond Oxygenation at Remote Methylenic Sites Enabled by Polarity Enhancement. J Am Chem Soc 2023; 145:22086-22096. [PMID: 37751483 PMCID: PMC10571082 DOI: 10.1021/jacs.3c07658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Indexed: 09/28/2023]
Abstract
A detailed study on the C(sp3)-H bond oxygenation reactions with H2O2 catalyzed by the [Mn(OTf)2(TIPSmcp)] complex at methylenic sites of cycloalkyl and 1-alkyl substrates bearing 19 different electron-withdrawing functional groups (EW FGs) was carried out. Oxidations in MeCN were compared to the corresponding ones in the strong hydrogen bond donating (HBD) solvents 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and nonafluoro tert-butyl alcohol (NFTBA). Formation of the products deriving from oxygenation at the most remote methylenic sites was observed, with yields, product ratios (PR) for oxygenation at the most remote over the next methylenic sites, and associated site-selectivities that significantly increased going from MeCN to HFIP and NFTBA. Unprecedented site-selectivities were obtained in the oxidation of cyclohexyl, cycloheptyl, cyclooctyl, 1-pentyl, 1-hexyl, and 1-heptyl substrates, approaching >99%, >99%, 90%, >99%, 93%, and 88% (PR >99, >99, 9.4, >99, 14, and 7.5) with cyclohexyl-2-pyridinecarboxylate, cycloheptyl-2-pyridinecarboxylate, cyclooctyl-4-nitrobenzenesulfonamide, 1-pentyl-3,5-dinitrobenzoate, 1-hexyl-3,5-dinitrobenzoate, and 1-heptyl-3,5-dinitrobenzoate, respectively. The results are rationalized on the basis of a polarity enhancement effect via synergistic electronic deactivation of proximal methylenic sites imparted by the EWG coupled to solvent HB. Compared to previous procedures, polarity enhancement provides the opportunity to tune site-selectivity among multiple methylenes in different substrate classes, extending the strong electronic deactivation determined by native EWGs by two carbon atoms. This study uncovers a simple procedure for predictable, high-yielding, and highly site-selective oxidation at remote methylenes of cycloalkyl and 1-alkyl substrates that occurs under mild conditions, with a large substrate scope, providing an extremely powerful tool to be implemented in synthetically useful procedures.
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Affiliation(s)
- Sergio Sisti
- Dipartimento
di Scienze e Tecnologie Chimiche, Università
“Tor Vergata”, Via della Ricerca Scientifica, 1, I-00133 Rome, Italy
| | - Marco Galeotti
- QBIS
Research Group, Institut de Química Computacional i Catàlisi
(IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Filippo Scarchilli
- QBIS
Research Group, Institut de Química Computacional i Catàlisi
(IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Michela Salamone
- Dipartimento
di Scienze e Tecnologie Chimiche, Università
“Tor Vergata”, Via della Ricerca Scientifica, 1, I-00133 Rome, Italy
| | - Miquel Costas
- QBIS
Research Group, 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
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7
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Chen J, Song W, Yao J, Wu Z, Lee YM, Wang Y, Nam W, Wang B. Hydrogen Bonding-Assisted and Nonheme Manganese-Catalyzed Remote Hydroxylation of C-H Bonds in Nitrogen-Containing Molecules. J Am Chem Soc 2023; 145:5456-5466. [PMID: 36811463 DOI: 10.1021/jacs.2c13832] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The development of catalytic systems capable of oxygenating unactivated C-H bonds with excellent site-selectivity and functional group tolerance under mild conditions remains a challenge. Inspired by the secondary coordination sphere (SCS) hydrogen bonding in metallooxygenases, reported herein is an SCS solvent hydrogen bonding strategy that employs 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as a strong hydrogen bond donor solvent to enable remote C-H hydroxylation in the presence of basic aza-heteroaromatic rings with a low loading of a readily available and inexpensive manganese complex as a catalyst and hydrogen peroxide as a terminal oxidant. We demonstrate that this strategy represents a promising compliment to the current state-of-the-art protection approaches that rely on precomplexation with strong Lewis and/or Brønsted acids. Mechanistic studies with experimental and theoretical approaches reveal the existence of a strong hydrogen bonding between the nitrogen-containing substrate and HFIP, which prevents the catalyst deactivation by nitrogen binding and deactivates the basic nitrogen atom toward oxygen atom transfer and the α-C-H bonds adjacent to the nitrogen center toward H-atom abstraction. Moreover, the hydrogen bonding exerted by HFIP has also been demonstrated not only to facilitate the O-O bond heterolytic cleavage of a putative MnIII-OOH precursor to generate MnV(O)(OC(O)CH2Br) as an active oxidant but also to affect the stability and the activity of MnV(O)(OC(O)CH2Br).
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Affiliation(s)
- Jie Chen
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
| | - Wenxun Song
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
| | - Jinping Yao
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
| | - Zhimin Wu
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong Wang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Bin Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
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8
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Long Y, He J, Zhang H, Chen Y, Liu K, Fu J, Li H, Zhu L, Lin Z, Stefancu A, Cortes E, Zhu M, Liu M. Highly Selective Monomethylation of Amines with CO 2 /H 2 via Ag/Al 2 O 3 as a Catalyst. Chemistry 2023; 29:e202203152. [PMID: 36626646 DOI: 10.1002/chem.202203152] [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: 10/10/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/12/2023]
Abstract
The selective synthesis of monomethylated amines with CO2 is particularly challenging because the formation of tertiary amines is thermodynamically more favorable. Herein, a new strategy for the controllable synthesis of N-monomethylated amines from primary amines and CO2 /H2 is explored. First-principle calculations reveal that the dissociation of H2 via an heterolytic route reduces the reactivity of methylated amines and thus inhibit successive methylation. In situ DRIFTS proves the process of formation and decomposition of ammonium salt by secondary amine reversible binding with H+ on the Ag/Al2 O3 catalyst, thereby reducing its reactivity. Meanwhile, the energy barrier for the rate-determining step of monomethylation was much lower than that of overmethylation (0.34 eV vs. 0.58 eV) means amines monomethylation in preference to successive methylation. Under optimal reaction conditions, a variety of amines were converted to the corresponding monomethylated amines in good to excellent yields, and more than 90 % yield of product was obtained.
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Affiliation(s)
- Yan Long
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443, Guangzhou, P. R. China
| | - Jie He
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443, Guangzhou, P. R. China
| | - Hang Zhang
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
| | - Yingkang Chen
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
| | - Kang Liu
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
| | - Junwei Fu
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
| | - Hongmei Li
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China.,School of Materials Science and Engineering, Zhengzhou University, 450002, Zhengzhou, P. R. China
| | - Li Zhu
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
| | - Zhang Lin
- Chinese National Engineering Research Centre for Control &, Treatment of Heavy Metal Pollution, School of Metallurgy and Environment, Central South University, 410083, Changsha, China
| | - Andrei Stefancu
- Nanoinstitut München, Fakultät für Physik, Ludwig-Maximilians-Universität München, 80539, München, Germany
| | - Emiliano Cortes
- Nanoinstitut München, Fakultät für Physik, Ludwig-Maximilians-Universität München, 80539, München, Germany
| | - Mingshan Zhu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443, Guangzhou, P. R. China
| | - Min Liu
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083, Changsha, P. R. China
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9
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Lasky MR, Salvador TK, Mukhopadhyay S, Remy MS, Vaid TP, Sanford MS. Photochemical C(sp 2 )-H Pyridination via Arene-Pyridinium Electron Donor-Acceptor Complexes. Angew Chem Int Ed Engl 2022; 61:e202208741. [PMID: 36100577 PMCID: PMC9828204 DOI: 10.1002/anie.202208741] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Indexed: 01/12/2023]
Abstract
This report describes the development of a photochemical method for C(sp2 )-H pyridination that leverages the photoexcitation of electron donor-acceptor (EDA) complexes. Experimental and DFT studies show that black light (λmax ≈350 nm) irradiation of solutions of protonated pyridines (acceptors) and aromatic C-H substrates (donors) results in single electron transfer to form aryl radical cation intermediates that can be trapped with pyridine nucleophiles under aerobic conditions. With some modification of the reaction conditions, this EDA activation mode is also effective for promoting the oxidatively triggered SN Ar pyridination of aryl halides. Overall, this report represents an inexpensive and atom-economical approach to photochemical pyridination reactions that eliminates the requirement of an exogenous photocatalyst.
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Affiliation(s)
- Matthew R. Lasky
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Tolani K. Salvador
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | | | | | - Thomas P. Vaid
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
| | - Melanie S. Sanford
- Department of ChemistryUniversity of Michigan930 North University AvenueAnn ArborMichigan48109USA
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10
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Mansson CMF, Burns NZ. Aqueous Amine-Tolerant [2+2] Photocycloadditions of Unactivated Olefins. J Am Chem Soc 2022; 144:19689-19694. [PMID: 36269089 DOI: 10.1021/jacs.2c08778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Kochi-Salomon reaction is the only photochemical [2+2] cycloaddition capable of combining two electronically unactivated olefins into a cyclobutane. Yet, the reaction has remained largely unexplored and suffers many drawbacks, most notably an intolerance to Lewis/Brønsted basic amines and amides. Since these groups are ubiquitous in biologically active pharmaceuticals, an amine-tolerant Kochi-Salomon reaction would greatly facilitate rapid exploration of novel drug scaffolds. Herein, we disclose a transformation that is run in water with the most widely available Cu(II) salts and mineral acids. Furthermore, we apply this methodology to synthesize a variety of amine-containing cyclobutanes, including known and novel pharmacological analogues.
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Affiliation(s)
- Carl M F Mansson
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Noah Z Burns
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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11
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Call A, Cianfanelli M, Besalú-Sala P, Olivo G, Palone A, Vicens L, Ribas X, Luis JM, Bietti M, Costas M. Carboxylic Acid Directed γ-Lactonization of Unactivated Primary C-H Bonds Catalyzed by Mn Complexes: Application to Stereoselective Natural Product Diversification. J Am Chem Soc 2022; 144:19542-19558. [PMID: 36228322 DOI: 10.1021/jacs.2c08620] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions that enable selective functionalization of strong aliphatic C-H bonds open new synthetic paths to rapidly increase molecular complexity and expand chemical space. Particularly valuable are reactions where site-selectivity can be directed toward a specific C-H bond by catalyst control. Herein we describe the catalytic site- and stereoselective γ-lactonization of unactivated primary C-H bonds in carboxylic acid substrates. The system relies on a chiral Mn catalyst that activates aqueous hydrogen peroxide to promote intramolecular lactonization under mild conditions, via carboxylate binding to the metal center. The system exhibits high site-selectivity and enables the oxidation of unactivated primary γ-C-H bonds even in the presence of intrinsically weaker and a priori more reactive secondary and tertiary ones at α- and β-carbons. With substrates bearing nonequivalent γ-C-H bonds, the factors governing site-selectivity have been uncovered. Most remarkably, by manipulating the absolute chirality of the catalyst, γ-lactonization at methyl groups in gem-dimethyl structural units of rigid cyclic and bicyclic carboxylic acids can be achieved with unprecedented levels of diastereoselectivity. Such control has been successfully exploited in the late-stage lactonization of natural products such as camphoric, camphanic, ketopinic, and isoketopinic acids. DFT analysis points toward a rebound type mechanism initiated by intramolecular 1,7-HAT from a primary γ-C-H bond of the bound substrate to a highly reactive MnIV-oxyl intermediate, to deliver a carbon radical that rapidly lactonizes through carboxylate transfer. Intramolecular kinetic deuterium isotope effect and 18O labeling experiments provide strong support to this mechanistic picture.
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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-17003, Catalonia, Spain
| | - Marco Cianfanelli
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Giorgio Olivo
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Andrea Palone
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain.,Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata", Via della Ricerca Scientifica 1, I-00133 Rome, Italy
| | - Laia Vicens
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Xavi Ribas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, 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-17003, Catalonia, Spain
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12
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Zhou J, Jia M, Song M, Huang Z, Steiner A, An Q, Ma J, Guo Z, Zhang Q, Sun H, Robertson C, Bacsa J, Xiao J, Li C. Chemoselective Oxyfunctionalization of Functionalized Benzylic Compounds with a Manganese Catalyst. Angew Chem Int Ed Engl 2022; 61:e202205983. [PMID: 35594169 PMCID: PMC9400980 DOI: 10.1002/anie.202205983] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Indexed: 11/06/2022]
Abstract
Whilst allowing for easy access to synthetically versatile motifs and for modification of bioactive molecules, the chemoselective benzylic oxidation reactions of functionalized alkyl arenes remain challenging. Reported in this study is a new non-heme Mn catalyst stabilized by a bipiperidine-based tetradentate ligand, which enables methylene oxidation of benzylic compounds by H2 O2 , showing high activity and excellent chemoselectivity under mild conditions. The protocol tolerates an unprecedentedly wide range of functional groups, including carboxylic acid and derivatives, ketone, cyano, azide, acetate, sulfonate, alkyne, amino acid, and amine units, thus providing a low-cost, more sustainable and robust pathway for the facile synthesis of ketones, increase of complexity of organic molecules, and late-stage modification of drugs.
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Affiliation(s)
- Jimei Zhou
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Minxian Jia
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Menghui Song
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Zhiliang Huang
- Department of ChemistryUniversity of LiverpoolLiverpoolL69 7ZDUK
| | | | - Qidong An
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Jianwei Ma
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Zhiyin Guo
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Qianqian Zhang
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Huaming Sun
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
| | - Craig Robertson
- Department of ChemistryUniversity of LiverpoolLiverpoolL69 7ZDUK
| | - John Bacsa
- Department of ChemistryEmory University1515 Dickey Dr.AtlantaGA 30322USA
| | - Jianliang Xiao
- Department of ChemistryUniversity of LiverpoolLiverpoolL69 7ZDUK
| | - Chaoqun Li
- Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710119China
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13
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Zhou J, Jia M, Song M, Huang Z, Steiner A, An Q, Ma J, Guo Z, Zhang Q, Sun H, Robertson CM, Bacsa J, Xiao J, Li C. Chemoselective Oxyfunctionalization of Functionalized Benzylic Compounds with a Manganese Catalyst. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jimei Zhou
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an CHINA
| | - Minxian Jia
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Menghui Song
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Zhiliang Huang
- University of Liverpool Department of Chemistry UNITED KINGDOM
| | | | - Qidong An
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Jianwei Ma
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Zhiyin Guo
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Qianqian Zhang
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | - Huaming Sun
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an UNITED KINGDOM
| | | | - John Bacsa
- Emory University Department of Chemistry UNITED KINGDOM
| | - Jianliang Xiao
- University of Liverpool Department of Chemistry Oxford Street L69 7ZD Liverpool UNITED KINGDOM
| | - Chaoqun Li
- Shaanxi Normal University School of Chemistry & Chemical Engineering Xi'an CHINA
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14
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The quest for magic: recent advances in C(sp 3)–H methylation. PURE APPL CHEM 2022. [DOI: 10.1515/pac-2021-1203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Frequently referred to as the “magic methyl” effect, the introduction of a methyl group into a biologically active molecule has the potential to drastically alter its physical and biological properties and significantly increase potency. This effect is most pronounced when the methyl group is added at the α-position of an aliphatic heterocycle or ortho to a large rotatable group on an aromatic ring. Although seminal developments in C–H activation strategies offered solutions to the latter, until recent years there had been no selective and functional-group-tolerant method for C(sp3)–H methylation at late stages of synthesis. For many years, the lack of a generally applicable methylation strategy necessitated arduous de novo synthesis approaches to access methylated drug candidates, and discouraged further investigation and understandings of the magic methyl effect. This review will provide a summary of the most recent advances that enabled non-directed late-stage C(sp3)–H methylation, including through hydride transfer, chemical or anodic oxidation, and photocatalytic hydrogen atom transfer.
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15
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Hahn PL, Lowe JM, Xu Y, Burns KL, Hilinski MK. Amine Organocatalysis of Remote, Chemoselective C(sp 3)-H Hydroxylation. ACS Catal 2022; 12:4302-4309. [PMID: 35529672 PMCID: PMC9075503 DOI: 10.1021/acscatal.2c00392] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We introduce an organocatalytic approach for oxaziridinium-mediated C-H hydroxylation that employs secondary amines as catalysts. We also demonstrate the advantages of this operationally simple catalytic strategy for achieving high yielding and highly selective remote hydroxylation of compounds bearing oxidation-sensitive functional groups such as alcohols, ethers, carbamates, and amides. By employing hexafluoroisopropanol as the solvent in the absence of water, a proposed hydrogen bonding effect leads to, among other advantages, as high as ≥99:1 chemoselectivity for remote aliphatic hydroxylation of 2° alcohols, an otherwise unsolved synthetic challenge normally complicated by substantial amounts of alcohol oxidation. Initial studies of the reaction mechanism indicate the formation of an oxaziridinium salt as the active oxidant, and a C-H oxidation step that proceeds in a stereospecific manner via concerted insertion or hydrogen atom transfer/radical rebound. Furthermore, preliminary results indicate that site selectivity can be affected by amine catalyst structure. In the long term, we anticipate that this will enable new strategies for catalyst control of selectivity based on the abundance of catalytic scaffolds that have proliferated over the last twenty years as a result of Nobel Prize-winning discoveries.
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Affiliation(s)
- Philip L. Hahn
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
| | - Jared M. Lowe
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
| | - Yubo Xu
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
| | - Kevin L. Burns
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
| | - Michael K. Hilinski
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, United States
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16
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Ali SZ, Budaitis BG, Fontaine DFA, Pace AL, Garwin JA, White MC. Allylic C-H amination cross-coupling furnishes tertiary amines by electrophilic metal catalysis. Science 2022; 376:276-283. [PMID: 35420962 DOI: 10.1126/science.abn8382] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intermolecular cross-coupling of terminal olefins with secondary amines to form complex tertiary amines-a common motif in pharmaceuticals-remains a major challenge in chemical synthesis. Basic amine nucleophiles in nondirected, electrophilic metal-catalyzed aminations tend to bind to and thereby inhibit metal catalysts. We reasoned that an autoregulatory mechanism coupling the release of amine nucleophiles with catalyst turnover could enable functionalization without inhibiting metal-mediated heterolytic carbon-hydrogen cleavage. Here, we report a palladium(II)-catalyzed allylic carbon-hydrogen amination cross-coupling using this strategy, featuring 48 cyclic and acyclic secondary amines (10 pharmaceutically relevant cores) and 34 terminal olefins (bearing electrophilic functionality) to furnish 81 tertiary allylic amines, including 12 drug compounds and 10 complex drug derivatives, with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z).
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Affiliation(s)
- Siraj Z Ali
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | - Brenna G Budaitis
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | - Devon F A Fontaine
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | - Andria L Pace
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | - Jacob A Garwin
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
| | - M Christina White
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA
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17
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Novaes LFT, Ho JSK, Mao K, Liu K, Tanwar M, Neurock M, Villemure E, Terrett JA, Lin S. Exploring Electrochemical C(sp 3)-H Oxidation for the Late-Stage Methylation of Complex Molecules. J Am Chem Soc 2022; 144:1187-1197. [PMID: 35015533 DOI: 10.1021/jacs.1c09412] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The "magic methyl" effect, a dramatic boost in the potency of biologically active compounds from the incorporation of a single methyl group, provides a simple yet powerful strategy employed by medicinal chemists in the drug discovery process. Despite significant advances, methodologies that enable the selective C(sp3)-H methylation of structurally complex medicinal agents remain very limited. In this work, we disclose a modular, efficient, and selective strategy for the α-methylation of protected amines (i.e., amides, carbamates, and sulfonamides) by means of electrochemical oxidation. Mechanistic analysis guided our development of an improved electrochemical protocol on the basis of the classic Shono oxidation reaction, which features broad reaction scope, high functional group compatibility, and operational simplicity. Importantly, this reaction system is amenable to the late-stage functionalization of complex targets containing basic nitrogen groups that are prevalent in medicinally active agents. When combined with organozinc-mediated C-C bond formation, our protocol enabled the direct methylation of a myriad of amine derivatives including those that have previously been explored for the "magic methyl" effect. This synthesis strategy thus circumvents multistep de novo synthesis that is currently necessary to access such compounds and has the potential to accelerate drug discovery efforts.
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Affiliation(s)
- Luiz F T Novaes
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850, United States
| | - Justin S K Ho
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850, United States
| | - Kaining Mao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850, United States
| | - Kaida Liu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mayank Tanwar
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Matthew Neurock
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Elisia Villemure
- Department of Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Jack A Terrett
- Department of Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Song Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14850, United States
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18
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He YG, Huang YK, Fan QQ, Zheng B, Luo YQ, Zhu XL, Shi XX. Copper(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp 3)-H bonds adjacent to 3,4-dihydroisoquinolines using air (O 2) as a clean oxidant. RSC Adv 2021; 11:29702-29710. [PMID: 35479555 PMCID: PMC9040818 DOI: 10.1039/d1ra05671a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 08/30/2021] [Indexed: 12/15/2022] Open
Abstract
A mild, efficient and eco-friendly method for the oxidation of 1-Bn-DHIQs to 1-Bz-DHIQs without concomitant excessive oxidation of 1-Bz-DHIQs to 1-Bz-IQs is very important for the syntheses of 1-Bz-DHIQ alkaloids and analogues. In this article, we developed a novel Cu(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp3)-H bonds adjacent to the C-1 positions of various 1-Bn-DHIQs. It was observed that when 0.2 equiv. of Cu(OAc)2·2H2O was used as the catalyst, 3.0 equiv. of AcOH was used as the additive and air (O2) was used as a clean oxidant, various 1-Bn-DHIQs could be efficiently oxidized to corresponding 1-Bz-DHIQs at 25 °C in DMSO. Especially, almost no concomitant excessive oxidation of 1-Bz-DHIQs to 1-Bz-IQs was observed during the above reaction. In addition, this method was successfully applied in the first total synthesis of the alkaloid canelillinoxine.
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Affiliation(s)
- Yun-Gang He
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Yong-Kang Huang
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Qi-Qi Fan
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Bo Zheng
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Yong-Qiang Luo
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Xing-Liang Zhu
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
| | - Xiao-Xin Shi
- Engineering Research Center of Pharmaceutical Process Chemistry of the Ministry of Education, School of Pharmacy, East China University of Science and Technology Shanghai 200237 People's Republic of China
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19
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Dutta S, Li B, Rickertsen DRL, Valles DA, Seidel D. C-H Bond Functionalization of Amines: A Graphical Overview of Diverse Methods. SYNOPEN 2021; 5:173-228. [PMID: 34825124 PMCID: PMC8612105 DOI: 10.1055/s-0040-1706051] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
This Graphical Review provides a concise overview of the manifold and mechanistically diverse methods that enable the functionalization of sp3 C-H bonds in amines and their derivatives.
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Affiliation(s)
- Subhradeep Dutta
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Bowen Li
- 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
| | - Daniel A Valles
- Center for Heterocyclic Compounds, 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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20
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Tian S, Wang C, Xia J, Wan J, Liu Y. Transition Metal‐Free, Free‐Radical Sulfenylation of the α‐C(
sp
3
)−H Bond in Arylacetamides and Its Application Toward 2‐Thiomethyl Benzoxazoles Synthesis. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100816] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Shanghui Tian
- College of Chemistry and Chemical Engineering Jiangxi Normal University 330022 Nanchang People's Republic of China
| | - Chaoli Wang
- College of Chemistry and Chemical Engineering Jiangxi Normal University 330022 Nanchang People's Republic of China
| | - Jianhui Xia
- College of Chemistry and Chemical Engineering Jiangxi Normal University 330022 Nanchang People's Republic of China
| | - Jie‐Ping Wan
- College of Chemistry and Chemical Engineering Jiangxi Normal University 330022 Nanchang People's Republic of China
| | - Yunyun Liu
- College of Chemistry and Chemical Engineering Jiangxi Normal University 330022 Nanchang People's Republic of China
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21
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Capaldo L, Ravelli D, Fagnoni M. Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C-H Bonds Elaboration. Chem Rev 2021; 122:1875-1924. [PMID: 34355884 PMCID: PMC8796199 DOI: 10.1021/acs.chemrev.1c00263] [Citation(s) in RCA: 357] [Impact Index Per Article: 119.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Direct photocatalyzed
hydrogen atom transfer (d-HAT) can be considered
a method of choice for the elaboration of
aliphatic C–H bonds. In this manifold, a photocatalyst (PCHAT) exploits the energy of a photon to trigger the homolytic
cleavage of such bonds in organic compounds. Selective C–H
bond elaboration may be achieved by a judicious choice of the hydrogen
abstractor (key parameters are the electronic character and the molecular
structure), as well as reaction additives. Different are the classes
of PCsHAT available, including aromatic ketones, xanthene
dyes (Eosin Y), polyoxometalates, uranyl salts, a metal-oxo porphyrin
and a tris(amino)cyclopropenium radical dication. The processes (mainly
C–C bond formation) are in most cases carried out under mild
conditions with the help of visible light. The aim of this review
is to offer a comprehensive survey of the synthetic applications of
photocatalyzed d-HAT.
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Affiliation(s)
- Luca Capaldo
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Davide Ravelli
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
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22
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Sarver PJ, Bissonnette NB, MacMillan DWC. Decatungstate-Catalyzed C( sp3)-H Sulfinylation: Rapid Access to Diverse Organosulfur Functionality. J Am Chem Soc 2021; 143:9737-9743. [PMID: 34161084 PMCID: PMC8627221 DOI: 10.1021/jacs.1c04722] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Here we report the direct conversion of strong, aliphatic C(sp3)-H bonds into the corresponding alkyl sulfinic acids via decatungstate photocatalysis. This transformation has been applied to a diverse range of C(sp3)-rich scaffolds, including natural products and approved pharmaceuticals, providing efficient access to complex sulfur-containing products. To demonstrate the broad potential of this methodology for the divergent synthesis of pharmaceutically relevant molecules, procedures for the diversification of the sulfinic acid products into a range of medicinally relevant functional groups have been developed.
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Affiliation(s)
- Patrick J Sarver
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States
| | - Noah B Bissonnette
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States
| | - David W C MacMillan
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States
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23
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Zhou L, Wei S, Lei Z, Zhu G, Zhang Z. Transition-Metal-Free α Csp 3 -H Cyanation of Sulfonamides. Chemistry 2021; 27:7103-7107. [PMID: 33769613 DOI: 10.1002/chem.202100902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Indexed: 12/18/2022]
Abstract
This report describes the site-selective α-functionalization of sulfonylamide derivatives through the in-situ generation of imine intermediates. The N-F sulfonylamides, which could facilitate the elimination to generate imines, are coupled with TBACN to efficiently and mildly afford α-amino cyanides. Comparing with Strecker reaction, this transformation offers a complementary strategy to efficiently construct α-amino cyanides from direct α C-H functionalization of sulfonylamindes. The reaction is also characterized by broad substrate scope and flash chromatography column free workup. More importantly, the new two-electron pathway to generate imines through manipulation of the leaving group allows us to achieve excellent α site-selectivity.
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Affiliation(s)
- Liejin Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, P. R. China
| | - Siqi Wei
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, P. R. China
| | - Ziran Lei
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, P. R. China
| | - Gangguo Zhu
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, P. R. China
| | - Zuxiao Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, 688 Yingbin Road, Jinhua, 321004, P. R. China
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24
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Vasilopoulos A, Krska SW, Stahl SS. C(sp 3)-H methylation enabled by peroxide photosensitization and Ni-mediated radical coupling. Science 2021; 372:398-403. [PMID: 33888639 PMCID: PMC8110093 DOI: 10.1126/science.abh2623] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/25/2021] [Indexed: 12/20/2022]
Abstract
The "magic methyl" effect describes the change in potency, selectivity, and/or metabolic stability of a drug candidate associated with addition of a single methyl group. We report a synthetic method that enables direct methylation of C(sp3)-H bonds in diverse drug-like molecules and pharmaceutical building blocks. Visible light-initiated triplet energy transfer promotes homolysis of the O-O bond in di-tert-butyl or dicumyl peroxide under mild conditions. The resulting alkoxyl radicals undergo divergent reactivity, either hydrogen-atom transfer from a substrate C-H bond or generation of a methyl radical via β-methyl scission. The relative rates of these steps may be tuned by varying the reaction conditions or peroxide substituents to optimize the yield of methylated product arising from nickel-mediated cross-coupling of substrate and methyl radicals.
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Affiliation(s)
| | | | - Shannon S Stahl
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA.
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25
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Yang Y, Zuo L, Wei K, Guo W. Water-Mediated Catalytic Decarboxylation Enabled Polysubstituted Furans and Allylic Alcohols with Exclusive (E)-Configurations. Org Lett 2021; 23:3195-3200. [DOI: 10.1021/acs.orglett.1c00929] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yulian Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an 710045, China
| | - Linhong Zuo
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an 710045, China
| | - Kun Wei
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Wusheng Guo
- Frontier Institute of Science and Technology (FIST), Xi’an Jiaotong University, Xi’an 710045, China
- Xi’an Key Laboratory of Sustainable Energy Materials Chemistry, Xi’an Jiaotong University, Xi’an 710049, China
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26
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Talukdar K, Sarkar T, Roy S, Punniyamurthy T. Pd-Catalyzed sp 3 C-H alkoxycarbonylation of 8-methylquinolines using Mo(CO) 6 as a CO surrogate. Chem Commun (Camb) 2021; 57:3359-3362. [PMID: 33666212 DOI: 10.1039/d1cc00465d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A Pd(ii)-catalyzed three-component sp3 C-H alkoxycarbonylation of 8-methylquinonlines (8-MQs) with alcohols is accomplished using the colorless crystalline Mo(CO)6 as a CO source. The protocol is compatible with a wide range of 8-MQs and alcohols, furnishing the carbonylated adducts in moderate to good yields. The substrate scope, functional group tolerance and natural product mutation are the important practical features.
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Affiliation(s)
- Kangkan Talukdar
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India.
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27
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Sahoo PK, Zhang Y, Das S. CO 2-Promoted Reactions: An Emerging Concept for the Synthesis of Fine Chemicals and Pharmaceuticals. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05681] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Prakash Kumar Sahoo
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Yu Zhang
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Shoubhik Das
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
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28
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Matsuoka K, Komami N, Kojima M, Mita T, Suzuki K, Maeda S, Yoshino T, Matsunaga S. Chemoselective Cleavage of Si-C(sp 3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate). J Am Chem Soc 2021; 143:103-108. [PMID: 33356223 DOI: 10.1021/jacs.0c11645] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
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Affiliation(s)
- Keitaro Matsuoka
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Narumi Komami
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Masahiro Kojima
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Tsuyoshi Mita
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.,JST, ERATO Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Kimichi Suzuki
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.,JST, ERATO Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.,Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Satoshi Maeda
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.,JST, ERATO Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.,Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Tatsuhiko Yoshino
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Shigeki Matsunaga
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.,Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Sapporo 060-0812, Japan
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29
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Oka S, Shigehiro Y, Kataoka Y, Ura Y. Secondary phosphine oxide-triggered selective oxygenation of a benzyl ligand on palladium. Chem Commun (Camb) 2020; 56:12977-12980. [PMID: 32996484 DOI: 10.1039/d0cc05572g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The oxygenation of a benzyl ligand in [PdBnCl(cod)] was dramatically accelerated by using secondary phosphine oxides (SPOs), selectively affording either BnOOH or BnOH, depending on the concentration of O2. The SPOs coordinate to palladium in the form of phosphinous acids, operating as Brønsted acids to facilitate further reaction with O2.
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Affiliation(s)
- Sayaka Oka
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Kitauoyanishi-machi, Nara 630-8506, Japan.
| | - Yuma Shigehiro
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Kitauoyanishi-machi, Nara 630-8506, Japan.
| | - Yasutaka Kataoka
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Kitauoyanishi-machi, Nara 630-8506, Japan.
| | - Yasuyuki Ura
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Kitauoyanishi-machi, Nara 630-8506, Japan.
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30
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Knezevic M, Heilmann M, Piccini GM, Tiefenbacher K. Überwindung der intrinsischen Reaktivität bei aliphatischer C‐H‐Oxidation: Bevorzugte C3/C4‐Oxidation von aliphatischen Ammoniumsubstraten. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Melina Knezevic
- Departement Chemie Universität Basel Mattenstrasse 24a 4058 Basel Schweiz
| | - Michael Heilmann
- Departement Chemie Universität Basel Mattenstrasse 24a 4058 Basel Schweiz
| | - Giovanni Maria Piccini
- Departement Chemie und Angewandte Biowissenschaften ETH Zürich c/o USI Campus, Via Giuseppe Buffi 13 CH-6900 Lugano Schweiz
- Facoltàdi Informatica Istituto di Scienze Computazionali Universitàdella SvizzeraItaliana (USI) Via Giuseppe Buffi 13 CH-6900 Lugano Schweiz
| | - Konrad Tiefenbacher
- Departement Chemie Universität Basel Mattenstrasse 24a 4058 Basel Schweiz
- Departement Biosysteme ETH Zürich Mattenstrasse 24 4058 Basel Schweiz
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31
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Knezevic M, Heilmann M, Piccini GM, Tiefenbacher K. Overriding Intrinsic Reactivity in Aliphatic C−H Oxidation: Preferential C3/C4 Oxidation of Aliphatic Ammonium Substrates. Angew Chem Int Ed Engl 2020; 59:12387-12391. [DOI: 10.1002/anie.202004242] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/20/2020] [Indexed: 01/15/2023]
Affiliation(s)
- Melina Knezevic
- Department of Chemistry University of Basel Mattenstrasse 24a 4058 Basel Switzerland
| | - Michael Heilmann
- Department of Chemistry University of Basel Mattenstrasse 24a 4058 Basel Switzerland
| | - Giovanni Maria Piccini
- Department of Chemistry and Applied Biosciences ETH Zurich c/o USI Campus, Via Giuseppe Buffi 13 CH-6900 Lugano Switzerland
- Facoltàdi Informatica Istituto di Scienze Computazionali Universitàdella SvizzeraItaliana (USI) Via Giuseppe Buffi 13 CH-6900 Lugano Switzerland
| | - Konrad Tiefenbacher
- Department of Chemistry University of Basel Mattenstrasse 24a 4058 Basel Switzerland
- Department of Biosystems Science and Engineering ETH Zurich Mattenstrasse 24 4058 Basel Switzerland
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32
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Robinson SG, Mack JBC, Alektiar SN, Du Bois J, Sigman MS. Electrochemical Ruthenium-Catalyzed C-H Hydroxylation of Amine Derivatives in Aqueous Acid. Org Lett 2020; 22:7060-7063. [PMID: 32419465 DOI: 10.1021/acs.orglett.0c01313] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The development of an electrochemically driven, ruthenium-catalyzed C-H hydroxylation reaction of amine-derived substrates bearing tertiary C-H bonds is described. The reaction is performed under constant current electrolysis in a divided cell to afford alcohol products in yields comparable to those of our previously reported process, which requires the use of stoichiometric H5IO6 for catalytic turnover. With aqueous acid as solvent, the cathodic electrode reaction simply involves the reduction of protons to evolve hydrogen gas. The optimized protocol offers a convenient, efficient, and atom-economical method for sp3-C-H bond oxidation.
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Affiliation(s)
- Sophia G Robinson
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - James B C Mack
- Department of Chemistry, Stanford University, 337 Campus Drive, Stanford, California 94305, United States
| | - Sara N Alektiar
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - J Du Bois
- Department of Chemistry, Stanford University, 337 Campus Drive, Stanford, California 94305, United States
| | - Matthew S Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
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33
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Native amine-directed site-selective C(sp3)-H arylation of primary aliphatic amines with aryl iodides. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2019.10.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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34
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Su B, Bunescu A, Qiu Y, Zuend SJ, Ernst M, Hartwig JF. Palladium-Catalyzed Oxidation of β-C(sp 3)-H Bonds of Primary Alkylamines through a Rare Four-Membered Palladacycle Intermediate. J Am Chem Soc 2020; 142:7912-7919. [PMID: 32216373 DOI: 10.1021/jacs.0c01629] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Site-selective functionalizations of C-H bonds are often achieved with a directing group that leads to five- or six-membered metallacyclic intermediates. Analogous reactions that occur through four-membered metallacycles are rare. We report a challenging palladium-catalyzed oxidation of primary C-H bonds β to nitrogen in an imine of an aliphatic amine, a process that occurs through a four-membered palladacyclc intermediate. The success of the reaction relies on the identification, by H/D exchange, of a simple directing group (salicylaldehyde) capable of inducing the formation of this small ring. To gain insight into the steps of the catalytic cycle of this unusual oxidation reaction, a series of mechanistic experiments and density functional theory (DFT) calculations were conducted. The experimental studies showed that cleavage of the C-H bond is rate-limiting and formation of the strained four-membered palladacycle is thermodynamically uphill. DFT calculations corroborated these conclusions and suggested that the presence of an intramolecular hydrogen bond between the oxygen of the directing group and hydroxyl group of the ligating acetic acid is crucial for stabilization of the palladacyclic intermediate.
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Affiliation(s)
- Bo Su
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Ala Bunescu
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Yehao Qiu
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Stephan J Zuend
- BASF Corporation, 46820 Fremont Boulevard, Fremont, California 94538, United States
| | - Martin Ernst
- BASF SE, Carl-Bosch-Straße 38, 67056 Ludwigshafen, Germany
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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35
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Sarver PJ, Bacauanu V, Schultz DM, DiRocco DA, Lam YH, Sherer EC, MacMillan DWC. The merger of decatungstate and copper catalysis to enable aliphatic C(sp3)–H trifluoromethylation. Nat Chem 2020; 12:459-467. [DOI: 10.1038/s41557-020-0436-1] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 02/03/2020] [Indexed: 12/24/2022]
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36
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Trowbridge A, Walton SM, Gaunt MJ. New Strategies for the Transition-Metal Catalyzed Synthesis of Aliphatic Amines. Chem Rev 2020; 120:2613-2692. [DOI: 10.1021/acs.chemrev.9b00462] [Citation(s) in RCA: 310] [Impact Index Per Article: 77.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Aaron Trowbridge
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Scarlett M. Walton
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- Oncology
- IMED Biotech Unit, AstraZeneca, Darwin Building, Unit 310, Cambridge Science Park, Milton Road, Cambridge CB4 0WG, United Kingdom
| | - Matthew J. Gaunt
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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37
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Warden E, Bartolotti L, Huo S, Li Y. Theoretical Probe to the Mechanism of Pt-Catalyzed C-H Acylation Reaction: Possible Pathways for the Acylation Reaction of a Platinacycle. Inorg Chem 2020; 59:555-562. [PMID: 31834795 DOI: 10.1021/acs.inorgchem.9b02835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density functional theory (DFT) and nudged elastic band (NEB) theory have been used to study the possible pathways for the acylation of cycloplatinated complex A derived from 2-phenoxypyridine, which is conceived as the key step in the platinum-catalyzed acylation of 2-aryloxypyridines. Geometry optimization indicates that the previously proposed intermediate, an arenium ion species as a result of analogous aromatic substitution, is not an energy minimum, but rather cationic Pt-arene η2-complex E is obtained as a stable intermediate. NEB simulations suggest that the minimum energy pathway for the acylation reaction has energy barrier of 33.6 kcal/mol and consists of the following steps: (1) Nucleophilic substitution at acetyl chloride by the platinum of the reactant A forms five-coordinate Pt(IV) acylplatinum complex B with an energy barrier of 21.7 kcal/mol. (2) B undergoes 1,2-acyl migration from the platinum to the cyclometalated carbon through a three-membered platinacycle transition state to give Pt-arene η2-complex E with an energy barrier of 14.0 kcal/mol. (3) E undergoes ligand exchange with chloride to form neutral Pt-arene η2-complex F. (4) F undergoes ligand substitution with acetonitrile to give the product and the energy barrier is small (10.6 kcal/mol). The rate-determining step is the 1,2-acyl migration step. It is interesting to note that intermediate F was not included in the proposed mechanism but was identified by the NEB simulations. Five-coordinate Pt(IV) acylplatinum complex B undergoes barrierless ligand coordination with chloride to form neutral formal oxidative addition acylplatinum complex D; however, D is less stable than reactant A by 2.9 kcal/mol, which also implies that the isolation of an oxidative addition product Pt(IV) complex may be very challenging. The direct reductive elimination of D to form product P has a higher energy barrier (36.6 kcal/mol).
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Affiliation(s)
- Elizabeth Warden
- Department of Chemistry , East Carolina University , Greenville , North Carolina 27858 , United States
| | - Libero Bartolotti
- Department of Chemistry , East Carolina University , Greenville , North Carolina 27858 , United States
| | - Shouquan Huo
- Department of Chemistry , East Carolina University , Greenville , North Carolina 27858 , United States
| | - Yumin Li
- Department of Chemistry , East Carolina University , Greenville , North Carolina 27858 , United States
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38
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Janssen M, De Vos DE. Regioselective C–H hydroxylation of n-alkanes using Shilov-type Pt catalysis in perfluorinated micro-emulsions. Catal Sci Technol 2020. [DOI: 10.1039/c9cy02320h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, the potential of combining Shilov-type PtII and micellar catalysis to realize the challenging terminal C–H hydroxylation of saturated n-alkanes using water as the reaction medium is demonstrated.
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Affiliation(s)
- Michiel Janssen
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions
- Department of Microbial and Molecular Systems
- KU Leuven
- 3001 Leuven
- Belgium
| | - Dirk E. De Vos
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions
- Department of Microbial and Molecular Systems
- KU Leuven
- 3001 Leuven
- Belgium
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39
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Plummer CM, Li L, Chen Y. The post-modification of polyolefins with emerging synthetic methods. Polym Chem 2020. [DOI: 10.1039/d0py01279c] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This Perspective highlights the present state of polyolefin post-modification research, especially concerning recently developed C–H functionalization chemistry. Remaining challenges and emerging strategies within the field have also been discussed.
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Affiliation(s)
- Christopher M. Plummer
- School of Materials Science and Engineering
- Sun Yat-sen University
- Guangzhou 510275
- China
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
| | - Le Li
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
- Sun Yat-sen University
- Guangzhou 510275
- China
- School of Chemistry
| | - Yongming Chen
- School of Materials Science and Engineering
- Sun Yat-sen University
- Guangzhou 510275
- China
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
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40
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Long Y, Liu S, Ma X, Lu L, He Y, Deng Y. One-pot synthesis of 1-butylpyrrolidine and its derivatives from aqueous ammonia and 1,4-butandiol over CuNiPd/ZSM-5 catalysts. NEW J CHEM 2020. [DOI: 10.1039/d0nj02224a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A straightforward and economical route for 1-butylpyrrolidine over CuNiPd/ZSM-5 catalysts.
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Affiliation(s)
- Yan Long
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
| | - Shimin Liu
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
| | - Xiangyuan Ma
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
| | - Liujin Lu
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
| | - Yude He
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
| | - Youquan Deng
- Centre for Green Chemistry and Catalysis
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- State Key Laboratory of Solid Lubrication
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
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41
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Catalytic C(sp 3)-H bond activation in tertiary alkylamines. Nat Chem 2019; 12:76-81. [PMID: 31863014 DOI: 10.1038/s41557-019-0393-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 11/14/2019] [Indexed: 12/21/2022]
Abstract
The development of robust catalytic methods to assemble tertiary alkylamines provides a continual challenge to chemical synthesis. In this regard, transformation of a traditionally unreactive C-H bond, proximal to the nitrogen atom, into a versatile chemical entity would be a powerful strategy for introducing functional complexity to tertiary alkylamines. A practical and selective metal-catalysed C(sp3)-H activation facilitated by the tertiary alkylamine functionality, however, remains an unsolved problem. Here, we report a Pd(II)-catalysed protocol that appends arene feedstocks to tertiary alkylamines via C(sp3)-H functionalization. A simple ligand for Pd(II) orchestrates the C-H activation step in favour of deleterious pathways. The reaction can use both simple and complex starting materials to produce a range of multifaceted γ-aryl tertiary alkylamines and can be rendered enantioselective. The enabling features of this transformation should be attractive to practitioners of synthetic and medicinal chemistry as well as in other areas that use biologically active alkylamines.
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42
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Zhao Z, Kong X, Wang W, Hao J, Wang Y. Direct Use of Unprotected Aliphatic Amines to Generate N-Heterocycles via β-C–H Malonylation with Iodonium Ylide. Org Lett 2019; 22:230-233. [DOI: 10.1021/acs.orglett.9b04213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Zhiguo Zhao
- School of Chemistry and Chemical Engineering, Key Laboratory of the Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, Shandong, China
| | - Xiangjin Kong
- School of Chemistry and Chemical Engineering, Key Laboratory of the Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, Shandong, China
| | - Wei Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of the Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, Shandong, China
| | - Jingcheng Hao
- School of Chemistry and Chemical Engineering, Key Laboratory of the Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, Shandong, China
| | - Yao Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of the Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, Shandong, China
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43
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Sarkar R, Mukhopadhyay C. Carbon-Hydrogen Bond Functionalization in Aqueous Medium: A Brief Review. CURRENT GREEN CHEMISTRY 2019. [DOI: 10.2174/2213346106666191019120048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the last few decades, considerable research has led to the introduction of selective and
efficient green as well as sustainable synthetic methods of functionalization of carbon-hydrogen bonds
to form new carbon-carbon and carbon-heteroatom bonds. In this emerging field, significant development
has been attained under various environmentally benign conditions including aqueous medium.
In this review, we have summarized the current development of C-H functionalization carried out in
an aqueous medium and its synthetic applications according to carbon-carbon and carbon-heteroatom
bond formations under green conditions.
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Affiliation(s)
- Rajib Sarkar
- Department of Chemistry, University of Calcutta, 92 APC Road, Kolkata-700009, India
| | - Chhanda Mukhopadhyay
- Department of Chemistry, University of Calcutta, 92 APC Road, Kolkata-700009, India
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44
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Yuan F, Hou ZL, Pramanick PK, Yao B. Site-Selective Modification of α-Amino Acids and Oligopeptides via Native Amine-Directed γ-C(sp3)-H Arylation. Org Lett 2019; 21:9381-9385. [DOI: 10.1021/acs.orglett.9b03607] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Feipeng Yuan
- MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic-Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, P. R. China
| | - Zhen-Lin Hou
- MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic-Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, P. R. China
| | - Pranab K. Pramanick
- MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic-Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, P. R. China
| | - Bo Yao
- MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic-Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, P. R. China
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45
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Romero EA, Chen G, Gembicky M, Jazzar R, Yu JQ, Bertrand G. Understanding the Activity and Enantioselectivity of Acetyl-Protected Aminoethyl Quinoline Ligands in Palladium-Catalyzed β-C(sp 3)-H Bond Arylation Reactions. J Am Chem Soc 2019; 141:16726-16733. [PMID: 31565934 DOI: 10.1021/jacs.9b06746] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chiral acetyl-protected aminoalkyl quinoline (APAQ) ligands were recently discovered to afford highly active and enantioselective palladium catalysts for the arylation of methylene C(sp3)-H bonds, and herein, we investigate the origins of these heightened properties. Unprecedented amide-bridged APAQ-Pd dimers were predicted by density functional theory (DFT) calculations and were confirmed by single-crystal X-ray diffraction studies. Comparison of structural features between APAQ-Pd complexes and an acetyl-protected aminoethylpyridine APAPy-Pd complex strongly suggests that the high activity of the former originates from the presence of the quinoline ring, which slows the formation of the off-cycle palladium dimer. Furthermore, steric topographic maps for a representative subset of monomeric, monoligated palladium complexes allowed us to draw a unique parallel between the three-dimensional structures of these catalysts and their reported asymmetric induction in β-C(sp3)-H bond arylation reactions. Finally, cooperative noncovalent interactions present between the APAQ ligand and the substrate were identified as a crucial factor for imparting selectivity between chemically equivalent methylenic C(sp3)-H bonds prior to concerted metalation deprotonation activation.
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Affiliation(s)
- Erik A Romero
- UCSD-CNRS Joint Research Laboratory (UMI 3555), Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0358 , United States
| | - Gang Chen
- Department of Chemistry , The Scripps Research Institute , 10550 N. Torrey Pines Road , La Jolla , California 92037 , United States
| | - Milan Gembicky
- UCSD-CNRS Joint Research Laboratory (UMI 3555), Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0358 , United States
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Laboratory (UMI 3555), Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0358 , United States
| | - Jin-Quan Yu
- Department of Chemistry , The Scripps Research Institute , 10550 N. Torrey Pines Road , La Jolla , California 92037 , United States
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (UMI 3555), Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093-0358 , United States
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Hu C, Hong G, Nahide PD, He Y, Zhou C, Kozlowski MC, Wang L. C(sp 3)-H hydroxylation of fluorenes, oxindoles and benzofuranones with a Mg(NO 3) 2-HP(O)Ph 2 oxidation system. Org Chem Front 2019; 6:3167-3171. [PMID: 31516715 PMCID: PMC6739833 DOI: 10.1039/c9qo00778d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A novel oxidation system in which magnesium nitrate [Mg(NO3)2] is used as an oxidant in the presence of diphe-nylphosphine oxide [HP(O)Ph2] permits the C(sp3)-H hydroxylation of fluorenes, oxindoles, and benzofuranones. This method features high efficiency, good functional group tolerance, and operational simplicity. The synthetic utility is highlighted by further transformations to valuable organic materials.
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Affiliation(s)
- Chen Hu
- Key Laboratory for Advanced Materials, Institute of Fine Chemicals and School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China
| | - Gang Hong
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Pradip D Nahide
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yuchen He
- Key Laboratory for Advanced Materials, Institute of Fine Chemicals and School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China
| | - Chen Zhou
- Key Laboratory for Advanced Materials, Institute of Fine Chemicals and School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China
| | - Marisa C Kozlowski
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Limin Wang
- Key Laboratory for Advanced Materials, Institute of Fine Chemicals and School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China
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De A, Santra S, Hajra A, Zyryanov GV, Majee A. Visible-Light-Induced Regioselective C(sp3)-H Acyloxylation of Aryl-2H-azirines with (Diacetoxy)iodobenzene. J Org Chem 2019; 84:11735-11740. [DOI: 10.1021/acs.joc.9b01625] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Aramita De
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India
| | - Sougata Santra
- Department of Organic and Biomolecular Chemistry, Chemical Engineering Institute, Ural Federal University, 19 Mira Street, 620002 Yekaterinburg, Russian Federation
| | - Alakananda Hajra
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India
| | - Grigory V. Zyryanov
- Department of Organic and Biomolecular Chemistry, Chemical Engineering Institute, Ural Federal University, 19 Mira Street, 620002 Yekaterinburg, Russian Federation
- I. Ya. Postovskiy Institute of Organic Synthesis, Ural Division of the Russian Academy of Sciences, 22 Sofi Kovalevskoy Street, 620219 Yekaterinburg, Russian Federation
| | - Adinath Majee
- Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India
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48
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Kim RS, Surendranath Y. Electrochemical Reoxidation Enables Continuous Methane-to-Methanol Catalysis with Aqueous Pt Salts. ACS CENTRAL SCIENCE 2019; 5:1179-1186. [PMID: 31403070 PMCID: PMC6661865 DOI: 10.1021/acscentsci.9b00273] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Indexed: 05/31/2023]
Abstract
The direct conversion of methane to methanol would enable better utilization of abundant natural gas resources. In the presence of stoichiometric PtIV oxidants, PtII ions are capable of catalyzing this reaction in aqueous solutions at modest temperatures. Practical implementation of this chemistry requires a viable strategy for replacing or regenerating the expensive PtIV oxidant. Herein, we establish an electrochemical strategy for continuous regeneration of the PtIV oxidant to furnish overall electrochemical methane oxidation. We show that Cl-adsorbed Pt electrodes catalyze facile oxidation of PtII to PtIV at low overpotential without concomitant methanol oxidation. Exploiting this facile electrochemistry, we maintain the PtII/IV ratio during PtII-catalyzed methane oxidation via in situ monitoring of the solution potential coupled with dynamic modulation of the electric current. This approach leads to sustained methane oxidation catalysis with 70% selectivity for methanol.
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49
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Gupta A, Rahaman A, Bhadra S. Direct α-Chalcogenation of Aliphatic Carboxylic Acid Equivalents. Org Lett 2019; 21:6164-6168. [DOI: 10.1021/acs.orglett.9b02424] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Aniket Gupta
- Inorganic Materials and Catalysis Division, Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India
| | - Ajijur Rahaman
- Inorganic Materials and Catalysis Division, Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India
| | - Sukalyan Bhadra
- Inorganic Materials and Catalysis Division, Academy of Scientific and Innovative Research, CSIR-Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India
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50
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Janssen M, De Vos DE. Pt II -Catalyzed Hydroxylation of Terminal Aliphatic C(sp 3 )-H Bonds with Molecular Oxygen. Chemistry 2019; 25:10724-10734. [PMID: 31170321 DOI: 10.1002/chem.201901803] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/03/2019] [Indexed: 11/07/2022]
Abstract
The practical application of Shilov-type Pt catalysis to the selective hydroxylation of terminal aliphatic C-H bonds remains a formidable challenge, due to difficulties in replacing PtIV with a more economically viable oxidant, particularly O2 . We report the potential of employing FeCl2 as a suitable redox mediator to overcome the kinetic hurdles related to the direct use of O2 in the Pt reoxidation. For the selective conversion of butyric acid to γ-hydroxybutyric acid (GHB), a significantly enhanced catalyst activity and stability (turnover numbers (TON)>30) were achieved under 20 bar O2 in comparison to current state-of-the-art systems (TON<10). In this regard, essential reaction parameters affecting the overall activity were identified, along with specific additives to attain catalyst stability at longer reaction times. Notably, deactivation by reduction to Pt0 was prevented by the addition of monodentate pyridine derivatives, such as 2-fluoropyridine, but also by introducing varying partial pressures of N2 in the gaseous atmosphere. Finally, stability tests revealed the involvement of PtII and FeCl2 in catalyzing the non-selective overoxidation of GHB. Accordingly, in situ esterification with boric acid proved to be a suitable strategy to maintain enhanced selectivities at much higher conversions (TON>60). Altogether, a useful catalytic system for the selective hydroxylation of primary aliphatic C-H bonds with O2 is presented.
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Affiliation(s)
- Michiel Janssen
- Centre for Membrane separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, P.O. Box 2454, 3001, Leuven, Belgium
| | - Dirk E De Vos
- Centre for Membrane separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, P.O. Box 2454, 3001, Leuven, Belgium
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