1
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Deka H, Fridman N, Eisen MS. Temperature Dependence of the Ring Opening of Cyclopropene Imines on Thorium Metallocenes. Inorg Chem 2024; 63:9572-9578. [PMID: 38471108 PMCID: PMC11134510 DOI: 10.1021/acs.inorgchem.3c04213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/13/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024]
Abstract
The reactions of two highly strained cyclopropenimine ligands L1H and L2H (L1H = N1,N1,N2,N2-tetraisopropyl-3-iminocycloprop-1-ene-1,2-diamine, L2H = N1,N1,N2,N2-tetracyclohexyl-3-iminocycloprop-1-ene-1,2-diamine) with three thorium precursors Cp*2ThCl2, Cp*2Th(Cl)(CH3), and Cp*2Th(CH3)2 were studied. At -20 °C, L1H and L2H react with Cp*2ThCl2 to form Th1 (Th1 = Cp*2ThCl2(L1H)) and Th2 (Th2 = Cp*2ThCl2(L2H)), respectively, where the neutral ligand coordinates to the thorium metal center. Coordination of the ligand to the thorium metal center introduces aromaticity at the cyclopropene ring of the ligand. Reaction at room temperature results in the ring opening of the ligand to form Th3 (Th3 = Cp*2ThCl2((Z)-2,3-bis(diisopropylamino)acrylonitrile) and Th4 (Th4 = Cp*2ThCl2((Z)-2,3-bis(dicyclohexylamino)acrylonitrile), where the cyclopropenimine converts into a nitrile and coordinates to the thorium metal center. Reaction of L1H and L2H with Cp*2Th(Cl)(CH3) and/or Cp*2Th(CH3)2 at -20 °C results in a rapid methanolysis reaction and forms Cp*2Th(L1/L2)(CH3/Cl)-type complexes Th5 (Th5 = Cp*2Th(L1)(CH3)), Th6 (Th6 = Cp*2Th(L2)(CH3), Th7 (Th7 = Cp*2Th(L1)(Cl), and Th8 (Th8 = Cp*2Th(L2)(Cl). On the other hand, at room temperature, these reactions result in a ring opening of the ligand. Room-temperature reaction of L1H and L2H with Cp*2Th(CH3)2 results in Th9 (Th9 = Cp*2Th(CH3)((Z)-3-imino-N1,N1,N2,N2-tetraisopropylbut-1-ene-1,2-diamine) and Th10 (Th10 = Cp*2Th(CH3)((Z)-3-imino-N1,N1,N2,N2-tetracyclohexylbut-1-ene-1,2-diamine). Similarly, at room temperature, L1H and L2H react with Cp*2Th(Cl)(CH3) to form Th11 (Th11 = Cp*2Th(Cl)((Z)-3-imino- N1,N1,N2,N2-tetraisopropylbut-1-ene-1,2-diamine) and Th12 (Th12 = Cp*2Th(Cl)((Z)-3-imino-N1,N1,N2,N2-tetracyclohexylbut-1-ene-1,2-diamine). The ring-opening reaction is assisted by the nucleophilic attack of the thorium-coordinated methyl group to the highly strained cyclopropene imine carbon.
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Affiliation(s)
- Hemanta Deka
- Schulich
Faculty of Chemistry, Technion-Israel Institute
of Technology, Haifa
City 3200003, Israel
- Department
of Chemistry, Goalpara College, Goalpara 783101, Assam, India
| | - Natalia Fridman
- Schulich
Faculty of Chemistry, Technion-Israel Institute
of Technology, Haifa
City 3200003, Israel
| | - Moris S. Eisen
- Schulich
Faculty of Chemistry, Technion-Israel Institute
of Technology, Haifa
City 3200003, Israel
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2
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Carneiro SN, Laffoon JD, Luo L, Sanford MS. Benchmarking Trisaminocyclopropeniums as Mediators for Anodic Oxidation Reactions. J Org Chem 2024; 89:6389-6394. [PMID: 38607957 DOI: 10.1021/acs.joc.4c00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
This report benchmarks a tris(amino)cyclopropenium (TAC) salt as an electron-transfer mediator for anodic oxidation reactions in comparison to two known mediators: a triarylamine and a triarylimidazole derivative. The three mediators have redox potentials, diffusion coefficients, and heterogeneous electron transfer rates similar to those of glassy carbon electrodes in acetonitrile/KPF6. However, they differ significantly in their performance in two electro-organic reactions: anodic fluorination of a dithiane and anodic oxidation of 4-methoxybenzyl alcohol. These differences are rationalized based on variable stability in the presence of reaction components (e.g., NEt3·3HF, lutidine, and Cs2CO3) as well as very different rates of electron transfer with the organic substrate. Overall, this work highlights the advantages and disadvantages of each mediator and provides a foundation for expanding the applications of TACs in electro-organic synthesis moving forward.
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Affiliation(s)
- Sabrina N Carneiro
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joshua D Laffoon
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Long Luo
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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3
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Qian P, Zhu D, Wang X, Sun Q, Zhang S. Electrochemical Benzylic C(sp 3)-H Imidation Enabled by Benzoic Acid Derived Radicals. J Org Chem 2024; 89:6395-6404. [PMID: 38621116 DOI: 10.1021/acs.joc.4c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
We developed an electrochemical approach for benzylic C(sp3)-H imidation by virtue of the in situ generated oxygen-centered radicals (OCRs). The electrochemical imidation provides a complementary approach to giving distinct imide products compared with previous acyloxylation products. This protocol exhibits good site selectivity and broad substrate generality. Moreover, the utility of the OCR-mediated protocol was extended to the electrochemical oxidation of silane, and its robustness was also highlighted by the imidation of complex substrates, which would otherwise be inaccessible for previous approaches. A plausible reaction mechanism was proposed to rationalize the experimental observations.
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Affiliation(s)
- Peng Qian
- Engineering Research Center of Biomass Conversion and Pollution Prevention of Anhui Educational Institutions, Biomass-Derived, Functional Oligosaccharides Engineering Technology Research Center of Anhui Province, School of Chemistry and Material Engineering, Fuyang Normal University, Fuyang, Anhui 236037, China
| | - Dan Zhu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
| | - Xiaoli Wang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
| | - Qi Sun
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Sheng Zhang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
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4
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Liu J, Du J, Zhang LB, Li M, Guo W. Electrochemical Benzylic C-H Amination via N-Aminopyridinium. J Org Chem 2024; 89:6465-6473. [PMID: 38644574 DOI: 10.1021/acs.joc.4c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
An electrochemical protocol for benzylic C(sp3)-H aminopyridylation via direct C-H/N-H cross-coupling of alkylarenes with N-aminopyridinium triflate has been developed. This method features excellent site-selectivity, broad substrate scope, redox reagent-free and facile scalability. The generated benzylaminopyridiniums can be readily converted to benzylamines via electroreductive N-N bond cleavage.
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Affiliation(s)
- Jingwei Liu
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Jinyao Du
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Lin-Bao Zhang
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Ming Li
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Weisi Guo
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
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5
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East NR, Naumann R, Förster C, Ramanan C, Diezemann G, Heinze K. Oxidative two-state photoreactivity of a manganese(IV) complex using near-infrared light. Nat Chem 2024; 16:827-834. [PMID: 38332331 DOI: 10.1038/s41557-024-01446-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024]
Abstract
Highly reducing or oxidizing photocatalysts are a fundamental challenge in photochemistry. Only a few transition metal complexes with Earth-abundant metal ions have so far advanced to excited state oxidants. All these photocatalysts require high-energy light for excitation, and their oxidizing power has not been fully exploited due to energy dissipation before reaching the photoactive state. Here we demonstrate that the complex [Mn(dgpy)2]4+, based on Earth-abundant manganese and the tridentate 2,6-diguanidylpyridine ligand (dgpy), evolves to a luminescent doublet ligand-to-metal charge transfer (2LMCT) excited state (1,435 nm, 0.86 eV) with a lifetime of 1.6 ns after excitation with low-energy near-infrared light. This 2LMCT state oxidizes naphthalene to its radical cation. Substrates with extremely high oxidation potentials up to 2.4 V enable the [Mn(dgpy)2]4+ photoreduction via a high-energy quartet 4LMCT excited state with a lifetime of 0.78 ps, proceeding via static quenching by the solvent. This process minimizes free energy losses and harnesses the full photooxidizing power, and thus allows oxidation of nitriles and benzene using Earth-abundant elements and low-energy light.
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Affiliation(s)
- Nathan R East
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Charusheela Ramanan
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Max-Planck-Institute for Polymer Research, Mainz, Germany
| | - Gregor Diezemann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany.
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6
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Rani S, Aslam S, Lal K, Noreen S, Alsader KAM, Hussain R, Shirinfar B, Ahmed N. Electrochemical C-H/C-C Bond Oxygenation: A Potential Technology for Plastic Depolymerization. CHEM REC 2024; 24:e202300331. [PMID: 38063812 DOI: 10.1002/tcr.202300331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/23/2023] [Indexed: 03/10/2024]
Abstract
Herein, we provide eco-friendly and safely operated electrocatalytic methods for the selective oxidation directly or with water, air, light, metal catalyst or other mediators serving as the only oxygen supply. Heavy metals, stoichiometric chemical oxidants, or harsh conditions were drawbacks of earlier oxidative cleavage techniques. It has recently come to light that a crucial stage in the deconstruction of plastic waste and the utilization of biomass is the selective activation of inert C(sp3 )-C/H(sp3 ) bonds, which continues to be a significant obstacle in the chemical upcycling of resistant polyolefin waste. An appealing alternative to chemical oxidations using oxygen and catalysts is direct or indirect electrochemical conversion. An essential transition in the chemical and pharmaceutical industries is the electrochemical oxidation of C-H/C-C bonds. In this review, we discuss cutting-edge approaches to chemically recycle commercial plastics and feasible C-C/C-H bonds oxygenation routes for industrial scale-up.
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Affiliation(s)
- Sadia Rani
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Samina Aslam
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Kiran Lal
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Sobia Noreen
- Institute of Chemistry, University of Sargodha, Sargodha, 40100, Pakistan
| | | | - Riaz Hussain
- Department of Chemistry, University of Education Lahore, D.G. Khan Campus, 32200, Pakistan
| | - Bahareh Shirinfar
- West Herts College - University of Hertfordshire, Watford, WD17 3EZ, London, United Kingdom
| | - Nisar Ahmed
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, United Kingdom
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7
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Choi A, Goodrich OH, Atkins AP, Edwards MD, Tiemessen D, George MW, Lennox AJJ. Electrochemical Benzylic C(sp 3)-H Direct Amidation. Org Lett 2024; 26:653-657. [PMID: 38227550 PMCID: PMC10825869 DOI: 10.1021/acs.orglett.3c04012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 01/17/2024]
Abstract
Amide bonds are ubiquitous and found in a myriad of functional molecules. Although formed in a reliable and robust fashion, alternative amide bond disconnections provide flexibility and synthetic control. Herein we describe an electrochemical method to form the non-amide C-N bond from direct benzylic C(sp3)-H amidation. Our approach is applied toward the synthesis of secondary amides by coupling secondary benzylic substrates with substituted primary benzamides. The reaction has been scaled up to a multigram scale in flow.
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Affiliation(s)
- Anthony Choi
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | | | | | | | - David Tiemessen
- School
of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K.
| | - Michael W. George
- School
of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K.
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8
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Kang WJ, Zhang Y, Li B, Guo H. Electrophotocatalytic hydrogenation of imines and reductive functionalization of aryl halides. Nat Commun 2024; 15:655. [PMID: 38253534 PMCID: PMC10803379 DOI: 10.1038/s41467-024-45015-6] [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: 04/28/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
The open-shell catalytically active species, like radical cations or radical anions, generated by one-electron transfer of precatalysts are widely used in energy-consuming redox reactions, but their excited-state lifetimes are usually short. Here, a closed-shell thioxanthone-hydrogen anion species (3), which can be photochemically converted to a potent and long-lived reductant, is generated under electrochemical conditions, enabling the electrophotocatalytic hydrogenation. Notably, TfOH can regulate the redox potential of the active species in this system. In the presence of TfOH, precatalyst (1) reduction can occur at low potential, so that competitive H2 evolution can be inhibited, thus effectively promoting the hydrogenation of imines. In the absence of TfOH, the reducing ability of the system can reach a potency even comparable to that of Na0 or Li0, thereby allowing the hydrogenation, borylation, stannylation and (hetero)arylation of aryl halides to construct C-H, C-B, C-Sn, and C-C bonds.
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Affiliation(s)
- Wen-Jie Kang
- Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai, 200438, P.R. China
| | - Yanbin Zhang
- Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai, 200438, P.R. China.
| | - Bo Li
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91106, USA.
| | - Hao Guo
- Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai, 200438, P.R. China.
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9
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Gao J, He XC, Liu YL, Li KR, Guan JP, Chen HB, Xiang HY, Chen K, Yang H. Visible-Light-Induced Nickel-Catalyzed Cross-Coupling of Aryl Bromides with Nitriles. Org Lett 2023. [PMID: 38032230 DOI: 10.1021/acs.orglett.3c03458] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Herein, a visible-light-induced nickel-catalyzed cross-coupling of aryl bromide with nitrile has been reported. By utilization of readily available nitriles as carbonyl precursors, a range of structurally diverse aryl ketones were facilely constructed. The synthetic simplicity, mild reaction conditions, and acidic functional group tolerance would broaden the synthetic utilities of this developed protocol as an expedient alternative to Grignard/organolithium protocols.
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Affiliation(s)
- Jie Gao
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Xian-Chen He
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Yan-Ling Liu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Ke-Rong Li
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Jian-Ping Guan
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Hong-Bin Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
- Jiangxi Time Chemical Company, Ltd., Fuzhou 344800, P. R. China
| | - Hao-Yue Xiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Kai Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Hua Yang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
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10
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Struwe J, Ackermann L. Photoelectrocatalyzed undirected C-H trifluoromethylation of arenes: catalyst evaluation and scope. Faraday Discuss 2023; 247:79-86. [PMID: 37466161 DOI: 10.1039/d3fd00076a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
During the last few years, photoelectrocatalysis has evolved as an increasingly viable tool for molecular synthesis. Despite several recent reports on the undirected C-H functionalization of arenes, thus far, a detailed comparison of different catalysts is still missing. To address this, more than a dozen different mediators were employed in the trifluoromethylation of (hetero-)arenes to compare them in their efficacies.
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Affiliation(s)
- Julia Struwe
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
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11
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Zhong PF, Tu JL, Zhao Y, Zhong N, Yang C, Guo L, Xia W. Photoelectrochemical oxidative C(sp 3)-H borylation of unactivated hydrocarbons. Nat Commun 2023; 14:6530. [PMID: 37845202 PMCID: PMC10579347 DOI: 10.1038/s41467-023-42264-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023] Open
Abstract
Organoboron compounds are of high significance in organic synthesis due to the unique versatility of boryl substituents to access further modifications. The high demand for the incorporation of boryl moieties into molecular structures has witnessed significant progress, particularly in the C(sp3)-H borylation of hydrocarbons. Taking advantage of special characteristics of photo/electrochemistry, we herein describe the development of an oxidative C(sp3)-H borylation reaction under metal- and oxidant-free conditions, enabled by photoelectrochemical strategy. The reaction exhibits broad substrate scope (>57 examples), and includes the use of simple alkanes, halides, silanes, ketones, esters and nitriles as viable substrates. Notably, unconventional regioselectivity of C(sp3)-H borylation is achieved, with the coupling site of C(sp3)-H borylation selectively located in the distal methyl group. Our method is operationally simple and easily scalable, and offers a feasible approach for the one-step synthesis of high-value organoboron building blocks from simple hydrocarbons, which would provide ample opportunities for drug discovery.
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Affiliation(s)
- Ping-Fu Zhong
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Jia-Lin Tu
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Yating Zhao
- College of Chemical and Material Engineering, Quzhou University, Quzhou, 324000, China
| | - Nan Zhong
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Chao Yang
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Lin Guo
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
| | - Wujiong Xia
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, China.
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12
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Wang Y, Dana S, Long H, Xu Y, Li Y, Kaplaneris N, Ackermann L. Electrochemical Late-Stage Functionalization. Chem Rev 2023; 123:11269-11335. [PMID: 37751573 PMCID: PMC10571048 DOI: 10.1021/acs.chemrev.3c00158] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Indexed: 09/28/2023]
Abstract
Late-stage functionalization (LSF) constitutes a powerful strategy for the assembly or diversification of novel molecular entities with improved physicochemical or biological activities. LSF can thus greatly accelerate the development of medicinally relevant compounds, crop protecting agents, and functional materials. Electrochemical molecular synthesis has emerged as an environmentally friendly platform for the transformation of organic compounds. Over the past decade, electrochemical late-stage functionalization (eLSF) has gained major momentum, which is summarized herein up to February 2023.
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Affiliation(s)
| | | | | | - Yang Xu
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Yanjun Li
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Nikolaos Kaplaneris
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Lutz Ackermann
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
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13
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Edgecomb JM, Alektiar SN, Cowper NGW, Sowin JA, Wickens ZK. Ketyl Radical Coupling Enabled by Polycyclic Aromatic Hydrocarbon Electrophotocatalysts. J Am Chem Soc 2023; 145:20169-20175. [PMID: 37676728 PMCID: PMC10787642 DOI: 10.1021/jacs.3c06347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Herein, we report a new class of electrophotocatalysts, polycyclic aromatic hydrocarbons, that promote the reduction of unactivated carbonyl compounds to generate versatile ketyl radical intermediates. This catalytic platform enables previously challenging intermolecular ketyl radical coupling reactions, including those that classic reductants (e.g., SmI2/HMPA) have failed to promote. More broadly, this study outlines an approach to fundamentally expand the array of reactive radical intermediates that can be generated via electrophotocatalysis by obviating the need for rapid mesolytic cleavage following substrate reduction.
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Affiliation(s)
- Joseph M Edgecomb
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Sara N Alektiar
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Nicholas G W Cowper
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jennifer A Sowin
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Zachary K Wickens
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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14
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Urbiña-Alvarez J, Rincón-Carvajal S, Gamba-Sánchez D. Ammonia surrogates in the synthesis of primary amines. Org Biomol Chem 2023; 21:7036-7051. [PMID: 37575051 DOI: 10.1039/d3ob01202f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Primary amines are derivatives of ammonia in which one hydrogen atom is replaced by an alkyl or aryl group. Ammonia serves as the primary nitrogen source in amination reactions, and its utilization in solution or as a pure gas has witnessed notable advancements. However, the use of gaseous ammonia remains problematic in academic laboratory settings, while employing aqueous ammonia poses challenges in highly water-sensitive transformations. Consequently, the search for alternative sources of ammonia has garnered considerable attention among the organic chemistry community. This comprehensive literature review focuses on the use of ammonia surrogates in amination reactions, irrespective of the resulting intermediate. The review emphasizes the formation of the C-N bond and underscores the importance of generating intermediate products that can be readily transformed into primary amines through well-established reactions.
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Affiliation(s)
- Julia Urbiña-Alvarez
- Laboratory of Organic Synthesis, Bio and Organocatalysis, Chemistry Department, Universidad de Los Andes, Cra 1 No. 18A-12 Q:305, Bogotá 111711, Colombia.
| | - Sergio Rincón-Carvajal
- Laboratory of Organic Synthesis, Bio and Organocatalysis, Chemistry Department, Universidad de Los Andes, Cra 1 No. 18A-12 Q:305, Bogotá 111711, Colombia.
| | - Diego Gamba-Sánchez
- Laboratory of Organic Synthesis, Bio and Organocatalysis, Chemistry Department, Universidad de Los Andes, Cra 1 No. 18A-12 Q:305, Bogotá 111711, Colombia.
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15
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Ruos ME, Kinney RG, Ring OT, Doyle AG. A General Photocatalytic Strategy for Nucleophilic Amination of Primary and Secondary Benzylic C-H Bonds. J Am Chem Soc 2023; 145:18487-18496. [PMID: 37565772 DOI: 10.1021/jacs.3c04912] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
We report a visible-light photoredox-catalyzed method that enables nucleophilic amination of primary and secondary benzylic C(sp3)-H bonds. A novel amidyl radical precursor and organic photocatalyst operate in tandem to transform primary and secondary benzylic C(sp3)-H bonds into carbocations via sequential hydrogen atom transfer (HAT) and oxidative radical-polar crossover. The resulting carbocation can be intercepted by a variety of N-centered nucleophiles, including nitriles (Ritter reaction), amides, carbamates, sulfonamides, and azoles, for the construction of pharmaceutically relevant C(sp3)-N bonds under unified reaction conditions. Mechanistic studies indicate that HAT is amidyl radical-mediated and that the photocatalyst operates via a reductive quenching pathway. These findings establish a mild, metal-free, and modular protocol for the rapid diversification of C(sp3)-H bonds to a library of aminated products.
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Affiliation(s)
- Madeline E Ruos
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - R Garrison Kinney
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Oliver T Ring
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
- Early Chemical Development, Pharmaceutical Sciences, Biopharmaceuticals R&D, AstraZeneca, Gothenburg, SE-431 83 Mölndal, Sweden
| | - Abigail G Doyle
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
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16
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Li A, Li X, Ma F, Gao H, Li H. Cyclization of Azobenzenes Via Electrochemical Oxidation Induced Benzylic Radical Generation. Org Lett 2023; 25:5978-5983. [PMID: 37548915 DOI: 10.1021/acs.orglett.3c02099] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
An electrochemical oxidation-induced cyclization of ortho-alkyl-substituted azobenzenes has been developed. The direct electrochemical benzylic C-H functionalization with respect to azobenzenes could proceed in the absence of any catalyst or external chemical oxidant to afford a number of 2H-indazole derivatives in moderate to good yields. This protocol enables the reuse of the byproduct to the same 2H-indazoles, thus significantly reducing pollution discharge in synthetic chemistry.
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Affiliation(s)
- Anni Li
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, P. R. China
| | - Xiangyi Li
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, P. R. China
| | - Fang Ma
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, P. R. China
| | - Hui Gao
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, P. R. China
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Hongji Li
- Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, P. R. China
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17
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Lepori M, Schmid S, Barham JP. Photoredox catalysis harvesting multiple photon or electrochemical energies. Beilstein J Org Chem 2023; 19:1055-1145. [PMID: 37533877 PMCID: PMC10390843 DOI: 10.3762/bjoc.19.81] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/07/2023] [Indexed: 08/04/2023] Open
Abstract
Photoredox catalysis (PRC) is a cutting-edge frontier for single electron-transfer (SET) reactions, enabling the generation of reactive intermediates for both oxidative and reductive processes via photon activation of a catalyst. Although this represents a significant step towards chemoselective and, more generally, sustainable chemistry, its efficacy is limited by the energy of visible light photons. Nowadays, excellent alternative conditions are available to overcome these limitations, harvesting two different but correlated concepts: the use of multi-photon processes such as consecutive photoinduced electron transfer (conPET) and the combination of photo- and electrochemistry in synthetic photoelectrochemistry (PEC). Herein, we review the most recent contributions to these fields in both oxidative and reductive activations of organic functional groups. New opportunities for organic chemists are captured, such as selective reactions employing super-oxidants and super-reductants to engage unactivated chemical feedstocks, and scalability up to gram scales in continuous flow. This review provides comparisons between the two techniques (multi-photon photoredox catalysis and PEC) to help the reader to fully understand their similarities, differences and potential applications and to therefore choose which method is the most appropriate for a given reaction, scale and purpose of a project.
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Affiliation(s)
- Mattia Lepori
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
| | - Simon Schmid
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
| | - Joshua P Barham
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany
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18
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Zhang Y, Sun X, Su JH, Li T, Du C, Li K, Sun Q, Zha Z, Wang Z. Switchable Direct Oxygenative Arylation of C(sp 3)-H Bonds via Electrophotocatalysis. Org Lett 2023; 25:5067-5072. [PMID: 37387463 DOI: 10.1021/acs.orglett.3c01751] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
A metal-free electrophotochemical C(sp3)-H arylation was developed under mild conditions. This method enables a switchable synthesis of diaryl alcohols and diaryl alkanes from inactive benzylic carbons. More importantly, a cheap and safe mediator N-chlorosuccinimide (NCS) was developed, which was employed for the hydrogen atom transfer (HAT) process of the benzylic C-H bond. In addition, this active radical was captured and identified by electron paramagnetic resonance (EPR).
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Affiliation(s)
- Yan Zhang
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiang Sun
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ji-Hu Su
- CAS Key Laboratory of Microscale Magnetic Resonance, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tong Li
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chengbin Du
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Kuiliang Li
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qi Sun
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhenggen Zha
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhiyong Wang
- Hefei National Center for Physical Sciences at Microscale, Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
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19
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Xu Y, Li Q, Ye R, Xu B, Zhou X. Electrochemical Oxidative C-H Amination through a Ritter-Type Reaction. J Org Chem 2023. [PMID: 37262003 DOI: 10.1021/acs.joc.3c00609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A straightforward strategy for direct benzylic C-H bond amination via an electrochemical Ritter-type reaction is developed. The reaction demonstrates simpler and milder reaction conditions over the existing methods without extra mediator. Moderate to excellent yields up to 94% of the desired amide products were obtained with a broad substrate scope. The removal of the Ac group by a simple step can afford NH-free benzylic amines, providing a suitable approach for the late-stage functionalization of bioactive molecules.
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Affiliation(s)
- Yiwen Xu
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Qiang Li
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Runyou Ye
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Buyi Xu
- National Anti-Drug Laboratory Sichuan Regional Center, 36 Yunling Road, Chengdu, Sichuan 610200, P.R. China
| | - Xiangge Zhou
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
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20
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Qian L, Shi M. Contemporary photoelectrochemical strategies and reactions in organic synthesis. Chem Commun (Camb) 2023; 59:3487-3506. [PMID: 36857689 DOI: 10.1039/d3cc00437f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
In recent years, with the development of organic synthetic chemistry, a variety of organic synthetic methods have been discovered and applied in practical production. Photochemistry and electrochemistry have been widely used in organic synthesis recently due to their advantages such as mild conditions and green and environmental protection and have now been developed into two of the most massive synthetic strategies in the field of organic synthesis. In order to further enhance the potential of photochemistry and electrochemistry and to overcome the limitations of each, organic synthetic chemists have worked to combine the two synthetic strategies together to develop photoelectrochemistry as a new synthetic method. Photoelectrochemistry achieves the complementary advantages and disadvantages of photochemistry and electrochemistry, avoids the problem of using stoichiometric oxidants or reductants in photochemistry and easy dimerization in electrochemistry, generates highly reactive reaction intermediates under mild conditions, and achieves reactions that are difficult to accomplish by single photochemistry or electrochemistry. This review summarizes the research progress in the field of photoelectrochemistry from the perspective of photoelectro-chemical catalysts in recent years, analyzes the catalytic mechanism of various catalysts in detail, and gives a brief outlook on the research direction and development prospects in this field.
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Affiliation(s)
- Ling Qian
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P. R. China
| | - Min Shi
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P. R. China
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Science, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.
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21
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Chen X, Lian Z, Kramer S. Enantioselective Intermolecular Radical Amidation and Amination of Benzylic C-H Bonds via Dual Copper and Photocatalysis. Angew Chem Int Ed Engl 2023; 62:e202217638. [PMID: 36721305 DOI: 10.1002/anie.202217638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/23/2023] [Accepted: 01/31/2023] [Indexed: 02/02/2023]
Abstract
A method for direct access to enantioenriched benzylic amides and carbamate-protected primary benzylamines by C-H functionalization is reported. The C-H substrate is used as limiting reagent with only a small excess of the unactivated amide or carbamate nucleophile. The enantioselective intermolecular dehydrogenative C-N bond formation is enabled by a combination of a chiral copper catalyst, a photocatalyst, and an oxidant, and it takes place under mild conditions, which allow for a broad substrate scope. The method is compatible with late-stage C-H functionalization, and it provides easy access to 15 N-labeled amides and amines starting from cheap 15 NH4 Cl.
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Affiliation(s)
- Xuemeng Chen
- Department of Chemistry, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
| | - Zhong Lian
- Department of Dermatology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital and West China School of Pharmacy, Sichuan University, China
| | - Søren Kramer
- Department of Chemistry, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
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22
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Chen ME, Gan ZY, Hu YH, Zhang FM. Tandem Oxidative Ritter Reaction/Hydration/Aldol Condensation of α-Arylketones with Propiolonitriles for the Construction of 3-Acyl-3-pyrrolin-2-ones. J Org Chem 2023; 88:3954-3964. [PMID: 36881939 DOI: 10.1021/acs.joc.2c02935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
A novel tandem oxidative Ritter reaction/hydration/aldol condensation of α-arylketones with substituted propiolonitriles has been developed. This protocol conveniently affords a wide range of functionalized 3-acyl-3-pyrrolin-2-ones through the efficient construction of four chemical bonds, a C-N bond, a C═C bond, and two C═O bonds, and the formation of one ring bearing an aza-quaternary center, which is ascribed to the strategical introduction of functionalized nitriles to this transformation. A reaction mechanism was proposed based on some control experiments.
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Affiliation(s)
- Meng-En Chen
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Zhang-Yan Gan
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Yue-Hong Hu
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Fu-Min Zhang
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
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23
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The future of organic electrochemistry current transfer. CHINESE JOURNAL OF CATALYSIS 2023. [DOI: 10.1016/s1872-2067(22)64197-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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24
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Cohen B, Lehnherr D, Sezen-Edmonds M, Forstater JH, Frederick MO, Deng L, Ferretti AC, Harper K, Diwan M. Emerging Reaction Technologies in Pharmaceutical Development: Challenges and Opportunities in Electrochemistry, Photochemistry, and Biocatalysis. Chem Eng Res Des 2023. [DOI: 10.1016/j.cherd.2023.02.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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25
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Yue H, Zhu C, Rueping M. Trisaminocyclopropenium ion (TAC +) enables contiguous CH bonds oxygenations via oxidative electrophotocatalysis. Sci Bull (Beijing) 2023:S2095-9273(23)00076-2. [PMID: 36774299 DOI: 10.1016/j.scib.2023.01.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Huifeng Yue
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Chen Zhu
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Magnus Rueping
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
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26
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Shen T, Li YL, Ye KY, Lambert TH. Electrophotocatalytic oxygenation of multiple adjacent C-H bonds. Nature 2023; 614:275-280. [PMID: 36473497 PMCID: PMC10436356 DOI: 10.1038/s41586-022-05608-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
Oxygen-containing functional groups are nearly ubiquitous in complex small molecules. The installation of multiple C-O bonds by the concurrent oxygenation of contiguous C-H bonds in a selective fashion would be highly desirable but has largely been the purview of biosynthesis. Multiple, concurrent C-H bond oxygenation reactions by synthetic means presents a challenge1-6, particularly because of the risk of overoxidation. Here we report the selective oxygenation of two or three contiguous C-H bonds by dehydrogenation and oxygenation, enabling the conversion of simple alkylarenes or trifluoroacetamides to their corresponding di- or triacetoxylates. The method achieves such transformations by the repeated operation of a potent oxidative catalyst, but under conditions that are sufficiently selective to avoid destructive overoxidation. These reactions are achieved using electrophotocatalysis7, a process that harnesses the energy of both light and electricity to promote chemical reactions. Notably, the judicious choice of acid allows for the selective synthesis of either di- or trioxygenated products.
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Affiliation(s)
- Tao Shen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
- Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian, China
| | - Yi-Lun Li
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian, China
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian, China.
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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27
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Abstract
The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C-H functionalization approaches that make use of low energy photons as a controllable energy source. Compared to traditional late-stage functionalization strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- and chemoselectivities. Merging the compelling benefits of photocatalysis with the late-stage functionalization workflow offers a potentially unmatched arsenal to tackle drug development campaigns and beyond. This Review highlights the photocatalytic late-stage C-H functionalization strategies of small-molecule drugs, agrochemicals, and natural products, classified according to the targeted C-H bond and the newly formed one. Emphasis is devoted to identifying, describing, and comparing the main mechanistic scenarios. The Review draws a critical comparison between established ionic chemistry and photocatalyzed radical-based manifolds. The Review aims to establish the current state-of-the-art and illustrate the key unsolved challenges to be addressed in the future. The authors aim to introduce the general readership to the main approaches toward photocatalytic late-stage C-H functionalization, and specialist practitioners to the critical evaluation of the current methodologies, potential for improvement, and future uncharted directions.
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Affiliation(s)
- Peter Bellotti
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Huan-Ming Huang
- School of Physical Science and Technology, ShanghaiTech University, 201210Shanghai, China
| | - Teresa Faber
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
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28
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Yang K, Wang Y, Luo S, Fu N. Electrophotochemical Metal-Catalyzed Enantioselective Decarboxylative Cyanation. Chemistry 2023; 29:e202203962. [PMID: 36638008 DOI: 10.1002/chem.202203962] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/13/2023] [Accepted: 01/13/2023] [Indexed: 01/14/2023]
Abstract
In contrast to the rapid growth of electrophotocatalysis in recent years, enantioselective catalytic reactions powered by this unique methodology remain rare. In this work, we report an electrophotochemical metal-catalyzed protocol for direct asymmetric decarboxylative cyanation of aliphatic carboxylic acids. The synergistic merging of electrophotochemical cerium catalysis and asymmetric electrochemical copper catalysis permits mild reaction conditions for the formation and utilization of the key carbon centered radicals by combining the power of light and electrical energy. Electrophotochemical cerium catalysis enables radical decarboxylation to produce alkyl radicals, which could be effectively intercepted by asymmetric electrochemical copper catalysis for the construction of C-CN bonds in a highly stereoselective fashion. This environmentally benign method smoothly converts a diverse array of arylacetic acids into the corresponding alkyl nitriles in good yields and enantioselectivities without using chemical oxidants or pre-functionalization of the acid substrates and can be readily scaled up.
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Affiliation(s)
- Kai Yang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Yukang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
- University of Chinese Academy of Sciences, 100049, Beijing, P. R. China
| | - Sanzhong Luo
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Niankai Fu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
- University of Chinese Academy of Sciences, 100049, Beijing, P. R. China
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29
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Wang XW, Li RX, Deng Y, Fu MQH, Zhao YN, Guan Z, He YH. Direct Hydroxylarylation of Benzylic Carbons (sp 3/sp 2/sp) via Radical-Radical Cross-Coupling Powered by Paired Electrolysis. J Org Chem 2023; 88:329-340. [PMID: 36563045 DOI: 10.1021/acs.joc.2c02363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Diaryl alcohol moieties are widespread in pharmaceuticals. Existing methods for the synthesis of diaryl alcohols require the use of pre-functionalized benzylic alcohols, aromatic aldehydes, or ketones as starting materials. Herein, the first convergent paired electrochemical approach to the direct hydroxylarylation of unactivated benzylic carbons (sp3/sp2/sp) is proposed. This protocol features direct functionalization of unactivated benzylic C(sp3)-H bonds and benzylic sp2/sp-carbons, mild conditions (open air, room temperature), an environmentally friendly procedure (without any external catalyst/mediator/additive), and direct access to sterically hindered alcohols from inexpensive and readily available alkyl/alkenyl/alkynylbenzenes. Mechanistic studies, including divided-cell experiments, isotope labeling, radical trapping, electron paramagnetic resonance, reaction kinetics, and cyclic voltammetry, strongly support the proposed radical-radical cross-coupling between transient ketyl radicals and persistent radical anions. Gram-scale synthesis and diversification of drug derivatives have visualized the tremendous potential of this protocol for practical applications.
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Affiliation(s)
- Xiao-Wen Wang
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Rui-Xue Li
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Yang Deng
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Ming-Qiu-Hao Fu
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Ya-Nan Zhao
- Analytical and Testing Center, Southwest University, Chongqing 400715, China
| | - Zhi Guan
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Yan-Hong He
- Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
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30
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Yu Y, Yuan Y, Ye KY. Electrochemical synthesis of vicinal azidoacetamides. Chem Commun (Camb) 2023; 59:422-425. [PMID: 36514900 DOI: 10.1039/d2cc06246a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Vicinal diamines are an important structural motif in bioactive natural products and pharmaceutical intermediates. Herein, an environmentally friendly and efficient electrochemical approach to azidoacetamides, as one variant of vicinal diamines, has been developed. This reaction features mild conditions and broad substrate scope, without the use of any chemical oxidant or transition-metal catalysts. The obtained vicinal azidoacetamides could be conveniently converted into various other vicinal diamine derivatives.
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Affiliation(s)
- Yi Yu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China.
| | - Yaofeng Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China.
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China.
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31
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Yu Y, Zhu XB, Yuan Y, Ye KY. An electrochemical multicomponent reaction toward C-H tetrazolation of alkyl arenes and vicinal azidotetrazolation of alkenes. Chem Sci 2022; 13:13851-13856. [PMID: 36544744 PMCID: PMC9710211 DOI: 10.1039/d2sc05423j] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022] Open
Abstract
The widespread use of tetrazoles in medicine, biology, and materials science continuously promotes the development of their efficient and selective syntheses. Despite the prosperous development of multicomponent reactions, the use of the most abundant and inexpensive chemical feedstocks, i.e., alkanes and alkenes, toward the preparation of diverse tetrazoles remains elusive. Herein, we developed an electrochemical multicomponent reaction (e-MCR) for highly efficient and selective C-H tetrazolation of alkyl arenes. When applied to alkenes, the corresponding vicinal azidotetrazoles were readily obtained, which were further demonstrated to be versatile building blocks and potential high-energy materials.
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Affiliation(s)
- Yi Yu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou UniversityFuzhou 350108China
| | - Xiao-Bin Zhu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou UniversityFuzhou 350108China
| | - Yaofeng Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou UniversityFuzhou 350108China
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou UniversityFuzhou 350108China
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32
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Stangier M, Scheremetjew A, Ackermann L. Chemo- and Site-Selective Electro-Oxidative Alkane Fluorination by C(sp 3 )-H Cleavage. Chemistry 2022; 28:e202201654. [PMID: 35844078 PMCID: PMC9804291 DOI: 10.1002/chem.202201654] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Indexed: 01/05/2023]
Abstract
Electrochemical fluorinations of C(sp3 )-H bonds with a nucleophilic fluoride source have been accomplished in a chemo- and site-selective fashion, avoiding the use of electrophilic F+ sources and stoichiometric oxidants. The introduced metal-free strategy exhibits high functional group tolerance, setting the stage for late-stage fluorinations of biorelevant motifs. The synthetic utility of the C(sp3 )-H fluorination was reflected by subsequent one-pot arylation of the generated benzylic fluorides.
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Affiliation(s)
- Maximilian Stangier
- Institut für Organische und Biomolekulare Chemie Wöhler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstrasse 237077GöttingenGermany
| | - Alexej Scheremetjew
- Institut für Organische und Biomolekulare Chemie Wöhler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstrasse 237077GöttingenGermany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie Wöhler Research Institute for Sustainable Chemistry (WISCh)Georg-August-Universität GöttingenTammannstrasse 237077GöttingenGermany
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33
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Abstract
Cyclopropenium ions are the smallest class of aromatic compounds, satisfying Hückel's rules of aromaticity with two π electrons within a three-membered ring. First prepared by Breslow in 1957, cyclopropenium ions have been found to possess extraordinary stability despite being both cationic and highly strained. In the 65 years since their first preparation, cyclopropenium ions have been the subject of innumerable studies concerning their synthesis, physical properties, and reactivity. However, prior to our work, the reactivity of these unique carbocations had not been exploited for reaction promotion or catalysis.Over the past 13 years, we have been exploring aromatic ions as unique and versatile building blocks for the development of catalysts for organic chemistry. A major portion of this work has been focused on leveraging the remarkable properties of the smallest of the aromatic ions─cyclopropeniums─as a design element in the invention of highly reactive catalysts. Indeed, because of its unique profile of hydrolytic stability, compact geometry, and relatively easy oxidizability, the cyclopropenium ring has proven to be a highly advantageous construction module for catalyst invention.In this Account, we describe some of our work using cyclopropenium ions as a key element in the design of novel catalysts. First, we discuss our early work aimed at promoting dehydrative reactions, starting with Appel-type chlorodehydrations of alcohols and carboxylic acids, cyclic ether formations, and Beckmann rearrangements and culminating in the realization of catalytic chlorodehydrations of alcohols and a catalytic Mitsunobu-type reaction. Next, we describe the development of cyclopropenimines as strong, neutral organic Brønsted bases and, in particular, the use of chiral cyclopropenimines for enantioselective Brønsted catalysis. We also describe the development of higher-order cyclopropenimine superbases. The use of tris(amino)cyclopropenium (TAC) ions as a novel class of phase-transfer catalysts is discussed for the reaction of epoxides with carbon dioxide. Next, we describe the formation of a cyclopropenone radical cation that has a portion of its spin density on the oxygen atom, leading to some peculiar metal ligand behavior. Finally, we discuss recent work that employs TAC electrophotocatalysts for oxidation reactions. The key intermediate for this chemistry is a TAC radical dication, which as an open-shell photocatalyst has remarkably strong excited-state oxidizing power. We describe the application of this strategy to transformations ranging from the oxidative functionalization of unactivated arenes to the regioselective derivatization of ethers, C-H aminations, vicinal C-H diaminations, and finally aryl olefin dioxygenations. Collectively, these catalytic platforms demonstrate the utility of charged aromatic rings, and cyclopropenium ions in particular, to enable unique advances in catalysis.
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Affiliation(s)
- Rebecca M Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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34
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Photoelectrochemical asymmetric catalysis enables site- and enantioselective cyanation of benzylic C–H bonds. Nat Catal 2022. [DOI: 10.1038/s41929-022-00855-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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Jia H, Ritter T. α-Thianthrenium Carbonyl Species: The Equivalent of an α-Carbonyl Carbocation. Angew Chem Int Ed Engl 2022; 61:e202208978. [PMID: 35895980 PMCID: PMC9804271 DOI: 10.1002/anie.202208978] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Indexed: 01/05/2023]
Abstract
Here we report an α-thianthrenium carbonyl species, as the equivalent of an α-carbonyl carbocation, which is generated by the radical conjugate addition of a trifluoromethyl thianthrenium salt to Michael acceptors. The reactivity allows for the synthesis of Cα -tetrasubstituted α- and β-amino acid analogues via a Ritter reaction by addition of acetonitrile. Addition of hydroxide, methoxide, and even fluoride can afford α-heteroatom substituted α-phenylpropanoates.
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Affiliation(s)
- Hao Jia
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany,Institute of Organic ChemistryRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Tobias Ritter
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
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36
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Tang SZ, Xiang K, Ye R, Chen ME, Yu JC, He ZJ, Zhang FM. Preparation of thioamides from alkyl bromides, nitriles, and hydrogen sulfide through a thio-Ritter-type reaction. Chem Commun (Camb) 2022; 58:11430-11433. [PMID: 36134562 DOI: 10.1039/d2cc04210j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel thio-Ritter-type reaction of alkyl bromides, nitriles, and hydrogen sulfide has been explored, providing a straightforward approach toward functionally important thioamides. This transformation features a broad substrate scope, operational simplicity, use of available feedstock chemicals, and late-stage functionalizations of bioactive molecules. The reaction mechanism is also proposed.
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Affiliation(s)
- Shi-Zhong Tang
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
| | - Kai Xiang
- Beijing Key Laboratory of Research and Application for Aerospace Green Propellants, Beijing Institute of Aerospace Testing Technology, Beijing 100074, China
| | - Rui Ye
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
| | - Meng-En Chen
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
| | - Jian-Chang Yu
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
| | - Zhi-Juan He
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
| | - Fu-Min Zhang
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
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37
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Tu HF, Jeandin A, Suero MG. Catalytic Synthesis of Cyclopropenium Cations with Rh-Carbynoids. J Am Chem Soc 2022; 144:16737-16743. [PMID: 36074785 PMCID: PMC9501905 DOI: 10.1021/jacs.2c07769] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we report the first catalytic one-step synthesis of cyclopropenium cations (CPCs) with readily available alkynes and hypervalent iodine reagents as carbyne sources. Key to the process is the catalytic generation of a novel Rh-carbynoid that formally transfers monovalent cationic carbynes (:+C-R) to alkynes via an oxidative [2+1] cycloaddition. Our process is able to synthesize a new type of CPC substituted with an ester group that underpins the regioselective attack of a broad range of carbon and heteroatomic nucleophiles, thus providing a new platform for the synthesis of valuable cyclopropenes difficult or not possible to make by current methodologies.
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Affiliation(s)
- Hang-Fei Tu
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Països Catalans 16, 43007 Tarragona, Spain
| | - Aliénor Jeandin
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Països Catalans 16, 43007 Tarragona, Spain.,Departament de Química Analítica i Química Orgánica, Universitat Rovira i Virgili, Calle Marcel.lí Domingo, 1, 43007 Tarragona, Spain
| | - Marcos G Suero
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Països Catalans 16, 43007 Tarragona, Spain
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38
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Wang Y, Li L, Fu N. Electrophotochemical Decarboxylative Azidation of Aliphatic Carboxylic Acids. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Yukang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liubo Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Niankai Fu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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39
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Jia H, Ritter T. α‐Thianthrenium Carbonyl Species: The Equivalent of an α‐Carbonyl Carbocation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208978] [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)
- Hao Jia
- Max-Planck-Institute für Kohlenforschung: Max-Planck-Institut fur Kohlenforschung Chemistry Kaiser-Wilhelm-Platz 1 45470 Muelheim an der Ruhr GERMANY
| | - Tobias Ritter
- Max-Planck-Institut für Kohlenforschung: Max-Planck-Institut fur Kohlenforschung Department of Organic Chemistry Kaiser-Wilhelm-Platz 1 45470 Muelheim an der Ruhr GERMANY
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40
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Narobe R, Murugesan K, Haag C, Schirmer TE, König B. C(sp 3)-H Ritter amination by excitation of in situ generated iodine(III)-BF 3 complexes. Chem Commun (Camb) 2022; 58:8778-8781. [PMID: 35843213 DOI: 10.1039/d2cc03283j] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visible light excitation of iodine(III)-BF3 complex enables the formation of carbocations from C(sp3)-H bonds. The complexes are generated catalytically from iodoarene, carboxylate ligand, the oxidizing agent Selectfluor, and the Lewis acid BF3. This modular catalytic system allows the formation of synthetically valuable amine derivatives without a metal- or photocatalyst.
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Affiliation(s)
- Rok Narobe
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Kathiravan Murugesan
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Christoph Haag
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Tobias Emanuel Schirmer
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Burkhard König
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
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41
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Ritter-type amination of C(sp 3)-H bonds enabled by electrochemistry with SO 42. Nat Commun 2022; 13:4138. [PMID: 35842447 PMCID: PMC9288499 DOI: 10.1038/s41467-022-31813-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 06/30/2022] [Indexed: 11/09/2022] Open
Abstract
By merging electricity with sulfate, the Ritter-type amination of C(sp3)-H bonds is developed in an undivided cell under room temperature. This method features broad substrate generality (71 examples, up to 93% yields), high functional-group compatibility, facile scalability, excellent site-selectivity and mild conditions. Common alkanes and electron-deficient alkylbenzenes are viable substrates. It also provides a straightforward protocol for incorporating C-deuterated acetylamino group into C(sp3)-H sites. Application in the synthesis or modification of pharmaceuticals or their derivatives and gram-scale synthesis demonstrate the practicability of this method. Mechanistic experiments show that sulfate radical anion, formed by electrolysis of sulfate, served as hydrogen atom transfer agent to provide alkyl radical intermediate. This method paves a convenient and flexible pathway for realizing various synthetically useful transformations of C(sp3)-H bonds mediated by sulfate radical anion generated via electrochemistry. The amination of C(sp3)–H bonds is an appealing and challenging task in organic synthesis. Here, by using an electrogenerated sulfate radical an HAT agent, the authors report a practical Ritter-type amination of C(sp3)–H bonds.
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42
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Huang H, Steiniger KA, Lambert TH. Electrophotocatalysis: Combining Light and Electricity to Catalyze Reactions. J Am Chem Soc 2022; 144:12567-12583. [PMID: 35816101 DOI: 10.1021/jacs.2c01914] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Visible-light photocatalysis and electrocatalysis are two powerful strategies for the promotion of chemical reactions that have received tremendous attention in recent years. In contrast, processes that combine these two modalities, an area termed electrophotocatalysis, have until recently remained quite rare. However, over the past several years a number of reports in this area have shown the potential of combining the power of light and electrical energy to realize new catalytic transformations. Electrophotocatalysis offers the ability to perform photoredox reactions without the need for large quantities of stoichiometric or superstoichiometric chemical oxidants or reductants by making use of an electrochemical potential as the electron source or sink. In addition, electrophotocatalysis is readily amenable to the generation of open-shell photocatalysts, which tend to have exceptionally strong redox potentials. In this way, potent yet selective redox reactions have been realized under relatively mild conditions. This Perspective highlights recent advances in the area of electrophotocatalysis and provides some possible avenues for future work in this growing area.
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Affiliation(s)
- He Huang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Keri A Steiniger
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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43
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Xiao W, Wu J. Recent advance in carbocation-catalyzed reactions. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.06.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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44
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Strekalova S, Kononov A, Budnikova Y. Amino Acids in Electrochemical Metal-Free Benzylic C-H Amidation. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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45
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Huang CY, Li J, Li CJ. Photocatalytic C(sp 3) radical generation via C-H, C-C, and C-X bond cleavage. Chem Sci 2022; 13:5465-5504. [PMID: 35694342 PMCID: PMC9116372 DOI: 10.1039/d2sc00202g] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/17/2022] [Indexed: 12/12/2022] Open
Abstract
C(sp3) radicals (R˙) are of broad research interest and synthetic utility. This review collects some of the most recent advancements in photocatalytic R˙ generation and highlights representative examples in this field. Based on the key bond cleavages that generate R˙, these contributions are divided into C–H, C–C, and C–X bond cleavages. A general mechanistic scenario and key R˙-forming steps are presented and discussed in each section. C(sp3) radicals (R˙) are of broad research interest and synthetic utility.![]()
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Affiliation(s)
- Chia-Yu Huang
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University 801 Sherbrooke Street W. Montreal Quebec H3A 0B8 Canada
| | - Jianbin Li
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University 801 Sherbrooke Street W. Montreal Quebec H3A 0B8 Canada
| | - Chao-Jun Li
- Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University 801 Sherbrooke Street W. Montreal Quebec H3A 0B8 Canada
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46
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Tang S, Guillot R, Grimaud L, Vitale MR, Vincent G. Electrochemical Benzylic C-H Functionalization with Isocyanides. Org Lett 2022; 24:2125-2130. [PMID: 35286094 DOI: 10.1021/acs.orglett.2c00364] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We report the challenging direct carbamoylation or cyanation of benzylic C(sp3)-H bonds with an isocyanide via an electrochemical process giving rise to structures that are encountered in several biologically relevant compounds and drugs. This transformation proceeds under mild conditions without the need for any external oxidant and avoids the necessity to start from a prefunctionalized benzylic substrate or the deployment of the cation pool method. The anodic oxidation of the benzylic position and the subsequent addition of the isocyanide lead to the formation of a C-C bond and to a nitrilium cation that hydrolyzes to yield α-aryl acetamide derivatives, whereas the elimination of a t-butyl cation delivers α-aryl acetonitrile derivatives.
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Affiliation(s)
- Shanyu Tang
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Laurence Grimaud
- Laboratoire des Biomolécules (LBM), Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Maxime R Vitale
- Laboratoire des Biomolécules (LBM), Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Guillaume Vincent
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
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47
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Zhang S, Li Y, Wang T, Li M, Wen L, Guo W. Electrochemical Benzylic C(sp 3)-H Isothiocyanation. Org Lett 2022; 24:1742-1746. [PMID: 35200030 DOI: 10.1021/acs.orglett.2c00415] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Selective C(sp3)-H isothiocyanation represents a significant strategy for the synthesis of isothiocyanate derivatives. We report herein an electrochemical benzylic isothiocyanation in a highly chemo- and site-selective manner under external oxidant-free conditions. The high chemoselectivity is attributed to the facile in situ isomerization of benzylic thiocyanates to isothiocyanates. Notably, the method exhibits high functional group compatibility and is suitable for late-stage functionalization of bioactive molecules.
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Affiliation(s)
- Shanxue Zhang
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Yufeng Li
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Tao Wang
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Ming Li
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Lirong Wen
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Weisi Guo
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
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48
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Feng T, Wang S, Liu Y, Liu S, Qiu Y. Electrochemical Desaturative β‐Acylation of Cyclic
N
‐Aryl Amines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tian Feng
- State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic Matter College of Chemistry Nankai University 94 Weijin Road Tianjin 300071 China
| | - Siyi Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic Matter College of Chemistry Nankai University 94 Weijin Road Tianjin 300071 China
| | - Yin Liu
- State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic Matter College of Chemistry Nankai University 94 Weijin Road Tianjin 300071 China
| | - Shouzhuo Liu
- State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic Matter College of Chemistry Nankai University 94 Weijin Road Tianjin 300071 China
| | - Youai Qiu
- State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic Matter College of Chemistry Nankai University 94 Weijin Road Tianjin 300071 China
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49
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Buglioni L, Raymenants F, Slattery A, Zondag SDA, Noël T. Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry. Chem Rev 2022; 122:2752-2906. [PMID: 34375082 PMCID: PMC8796205 DOI: 10.1021/acs.chemrev.1c00332] [Citation(s) in RCA: 208] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Indexed: 02/08/2023]
Abstract
Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing a plethora of opportunities to synthetic organic chemists. However, performing a photochemical transformation can be quite a challenge because of various issues related to the delivery of photons. These challenges have barred the widespread adoption of photochemical steps in the chemical industry. However, in the past decade, several technological innovations have led to more reproducible, selective, and scalable photoinduced reactions. Herein, we provide a comprehensive overview of these exciting technological advances, including flow chemistry, high-throughput experimentation, reactor design and scale-up, and the combination of photo- and electro-chemistry.
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Affiliation(s)
- Laura Buglioni
- Micro
Flow Chemistry and Synthetic Methodology, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, Het Kranenveld, Bldg 14—Helix, 5600 MB, Eindhoven, The Netherlands
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Fabian Raymenants
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Aidan Slattery
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Stefan D. A. Zondag
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Timothy Noël
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
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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: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [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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