1
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Yuan GC, Gao FL, Liu KW, Li M, Lin Y, Ye KY. Batch and Continuous-Flow Electrochemical Geminal Difluorination of Indeno[1,2- c]furans. Org Lett 2024. [PMID: 38968416 DOI: 10.1021/acs.orglett.4c02235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
An electrochemical gem-difluorination of indeno[1,2-c]furans using commercially available and easy-to-use triethylamine trihydrofluoride as both the electrolyte and fluorinating agent was developed. Remarkably, different reaction pathways of indeno[1,2-c]furans, i.e., paired electrolysis and net oxidation, are operative in a batch reactor and a continuous-flow microreactor to afford the corresponding gem-difluorinated indanones and indenones, respectively.
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Affiliation(s)
- Guo-Cai Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Fang-Ling Gao
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Kang-Wei Liu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Minggang Li
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Yuqi Lin
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Ke-Yin Ye
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
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2
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Avanthay M, Goodrich OH, Tiemessen D, Alder CM, George MW, Lennox AJJ. Bromide-Mediated Silane Oxidation: A Practical Counter-Electrode Process for Nonaqueous Deep Reductive Electrosynthesis. JACS AU 2024; 4:2220-2227. [PMID: 38938809 PMCID: PMC11200245 DOI: 10.1021/jacsau.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/29/2024]
Abstract
The counter-electrode process of an organic electrochemical reaction is integral for the success and sustainability of the process. Unlike for oxidation reactions, counter-electrode processes for reduction reactions remain limited, especially for deep reductions that apply very negative potentials. Herein, we report the development of a bromide-mediated silane oxidation counter-electrode process for nonaqueous electrochemical reduction reactions in undivided cells. The system is found to be suitable for replacing either sacrificial anodes or a divided cell in several reported reactions. The conditions are metal-free, use inexpensive reagents and a graphite anode, are scalable, and the byproducts are reductively stable and readily removed. We showcase the translation of a previously reported divided cell reaction to a >100 g scale in continuous flow.
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Affiliation(s)
- Mickaël
E. Avanthay
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Oliver H. Goodrich
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - David Tiemessen
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Catherine M. Alder
- Modalities
Platform Technologies, Molecular Modalities Discovery, GSK Medicines Research Centre, Stevenage SG1 2NY, U.K.
| | - Michael W. George
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
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3
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Rowett AC, Sweeting SG, Heard DM, Lennox AJJ. A Stoichiometric Haloform Coupling for Ester Synthesis with Secondary Alcohols. Angew Chem Int Ed Engl 2024; 63:e202400570. [PMID: 38533790 DOI: 10.1002/anie.202400570] [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: 01/09/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 03/28/2024]
Abstract
The haloform reaction from methyl ketones to carboxylic acids is one of the oldest known synthetic organic reactions, which has been used in myriad applications over the decades. The corresponding reaction to produce esters is, however, less developed, as the reaction is generally limited to simple, primary alcohols that are used in solvent-level quantities, thereby restricting the complexity of esters that can be directly formed. Herein, we detail the development of a general ester-forming haloform coupling reaction using one equivalent of alcohol. Mechanistic and kinetic modelling studies demonstrated that the key intermediates are formed under equilibrium, which facilitated the development of conditions that are amenable to secondary alcohols.
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Affiliation(s)
- Albert C Rowett
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Stephen G Sweeting
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - David M Heard
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alastair J J Lennox
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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4
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Dean AC, Randle EH, Lacey AJD, Marczak Giorio GA, Doobary S, Cons BD, Lennox AJJ. Alkene 1,3-Difluorination via Transient Oxonium Intermediates. Angew Chem Int Ed Engl 2024:e202404666. [PMID: 38695434 DOI: 10.1002/anie.202404666] [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: 03/07/2024] [Indexed: 06/21/2024]
Abstract
The 1,3-difunctionalization of unactivated alkenes is an under-explored transformation that leads to moieties that are otherwise challenging to prepare. Herein, we report a hypervalent iodine-mediated 1,3-difluorination of homoallylic (aryl) ethers to give unreported 1,3-difluoro-4-oxy groups with moderate to excellent diastereoselectivity. The transformation proceeds through a different mode of reactivity for 1,3-difunctionalization, in which a regioselective addition of fluoride opens a transiently formed oxonium intermediate to rearrange an alkyl chain. The optimized protocol is scalable and shown to proceed well with a variety of functional groups and substitution on the alkenyl chain, hence providing ready access to this fluorinated, conformationally controlled moiety.
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Affiliation(s)
- Alice C Dean
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K
| | - E Harvey Randle
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K
| | - Andrew J D Lacey
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K
| | | | - Sayad Doobary
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K
| | - Benjamin D Cons
- Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge, CB4 0QA, U.K
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5
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Tian X, Liu Y, Yakubov S, Schütte J, Chiba S, Barham JP. Photo- and electro-chemical strategies for the activations of strong chemical bonds. Chem Soc Rev 2024; 53:263-316. [PMID: 38059728 DOI: 10.1039/d2cs00581f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The employment of light and/or electricity - alternatively to conventional thermal energy - unlocks new reactivity paradigms as tools for chemical substrate activations. This leads to the development of new synthetic reactions and a vast expansion of chemical spaces. This review summarizes recent developments in photo- and/or electrochemical activation strategies for the functionalization of strong bonds - particularly carbon-heteroatom (C-X) bonds - via: (1) direct photoexcitation by high energy UV light; (2) activation via photoredox catalysis under irradiation with relatively lower energy UVA or blue light; (3) electrochemical reduction; (4) combination of photocatalysis and electrochemistry. Based on the types of the targeted C-X bonds, various transformations ranging from hydrodefunctionalization to cross-coupling are covered with detailed discussions of their reaction mechanisms.
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Affiliation(s)
- Xianhai Tian
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Yuliang Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
| | - Shahboz Yakubov
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Jonathan Schütte
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Shunsuke Chiba
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
| | - Joshua P Barham
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
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6
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Hooker LV, Bandar JS. Synthetic Advantages of Defluorinative C-F Bond Functionalization. Angew Chem Int Ed Engl 2023; 62:e202308880. [PMID: 37607025 PMCID: PMC10843719 DOI: 10.1002/anie.202308880] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 08/24/2023]
Abstract
Much progress has been made in the development of methods to both create compounds that contain C-F bonds and to functionalize C-F bonds. As such, C-F bonds are becoming common and versatile synthetic functional handles. This review summarizes the advantages of defluorinative functionalization reactions for small molecule synthesis. The coverage is organized by the type of carbon framework the fluorine is attached to for mono- and polyfluorinated motifs. The main challenges, opportunities and advances of defluorinative functionalization are discussed for each class of organofluorine. Most of the text focuses on case studies that illustrate how defluorofunctionalization can improve routes to synthetic targets or how the properties of C-F bonds enable unique mechanisms and reactions. The broader goal is to showcase the opportunities for incorporating and exploiting C-F bonds in the design of synthetic routes, improvement of specific reactions and advent of new methods.
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Affiliation(s)
- Leidy V Hooker
- Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jeffrey S Bandar
- Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, USA
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7
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Sun LW, Hu YF, Ji WJ, Zhang PY, Ma M, Shen ZL, Chu XQ. Selective and Controllable Defluorophosphination and Defluorophosphorylation of Trifluoromethylated Enones: An Auxiliary Function of the Carbonyl Group. Org Lett 2023; 25:3745-3749. [PMID: 37167193 DOI: 10.1021/acs.orglett.3c01215] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The auxiliary function of a carbonyl group in the tunable defluorophosphination and defluorophosphorylation of trifluoromethylated enones with P(O)-containing compounds was demonstrated. Controlled replacement of one or two fluorine atoms in trifluoromethylated enones while maintaining high chemo- and stereoselectivity was achieved under mild conditions, thus enabling diversity-oriented synthesis of skeletally diverse organophosphorus libraries─(Z)-difluoro-1,3-dien-1-yl phosphinates, (1Z,3E)-4-phosphoryl-4-fluoro-buta-1,3-dien-1-yl phosphinates, and (E)-4-phosphoryl-4-fluoro-1,3-but-3-en-1-ones─in good yields with excellent functional group tolerance.
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Affiliation(s)
- Li-Wen Sun
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Ya-Fei Hu
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Wen-Jun Ji
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Peng-Yuan Zhang
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Mengtao Ma
- Department of Chemistry and Materials Science, College of Science, Nanjing Forestry University, Nanjing 210037, China
| | - Zhi-Liang Shen
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xue-Qiang Chu
- Technical Institute of Fluorochemistry, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
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8
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Yang J, Gui J, Mu M, Liu S, Li J, Ren J, Wang Z. Synthesis of Difluoromethylated Carbinols via a HFIP-Promoted Hydroxydifluoromethylation of Aniline, Indole, and Pyrrole Derivatives with Difluoroacetaldehyde Ethyl Hemiacetal. J Org Chem 2023; 88:4790-4798. [PMID: 36989386 DOI: 10.1021/acs.joc.2c02812] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
A hexafluoroisopropanol (HFIP)-promoted hydroxydifluoromethylation of aniline, indole, and pyrrole derivatives with difluoroacetaldehyde ethyl hemiacetal has been developed. This protocol provides a facile and straightforward approach to access diverse difluoromethylated carbinols in good to excellent yields under mild conditions. Furthermore, gram-scale and synthetic derivatization experiments have also been demonstrated.
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Affiliation(s)
- Jianguo Yang
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P.R. China
- Collaborative Innovation Center for Advanced Organic Chemical Materials Co-Constructed by the Province and Ministry, Hubei University, Wuhan 430062, P.R. China
| | - Jing Gui
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P.R. China
| | - Miaomiao Mu
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P.R. China
| | - Saimei Liu
- Collaborative Innovation Center for Advanced Organic Chemical Materials Co-Constructed by the Province and Ministry, Hubei University, Wuhan 430062, P.R. China
| | - Jinshan Li
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P.R. China
| | - Jun Ren
- Collaborative Innovation Center for Advanced Organic Chemical Materials Co-Constructed by the Province and Ministry, Hubei University, Wuhan 430062, P.R. China
| | - Zhiming Wang
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P.R. China
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9
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Ghosh S, Qu ZW, Roy S, Grimme S, Chatterjee I. Photoredox Catalyzed Single C-F Bond Activation of Trifluoromethyl Ketones: A Solvent Controlled Divergent Access of gem-Difluoromethylene Containing Scaffolds. Chemistry 2023; 29:e202203428. [PMID: 36445786 DOI: 10.1002/chem.202203428] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 11/30/2022]
Abstract
Selective defluorinative functionalization of trifluoromethyl ketones is a long-standing challenge owing to the exhaustive mode of the process. To meet the demands for the installation of the gem-difluoromethylene unit for the construction of the molecular architectures of well-known pharmaceuticals and agrochemicals, a distinct pathway is thereby highly desirable. Here, a protocol is introduced that allows the divergent synthesis of gem-difluoromethylene group containing tetrahydrofuran derivatives and linear ketones via single C-F bond activation of trifluoromethyl ketones using visible-light photoredox catalysis in the presence of suitable olefins as trapping partner. The choice of appropriate solvent and catalyst plays a significant role in controlling the divergent behavior of this protocol. Highly reducing photo-excited catalysts are found to be responsible for the generation of α,α-difluoromethyl ketone (DFMK) radicals as the key intermediate via a SET process. This protocol also results in a high diastereoselectivity towards the formation of partially fluorinated cyclic ketal derivatives with simultaneous construction of one C-C and two C-O bonds. State-of-the-art DFT calculations are performed to address the origin of diastereoselectivity as well as the divergence of this protocol.
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Affiliation(s)
- Soumen Ghosh
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, Clausius Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Sourav Roy
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Clausius Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Indranil Chatterjee
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
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10
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Shen ZJ, Zhu C, Zhang X, Yang C, Rueping M, Guo L, Xia W. Organoboron Reagent-Controlled Selective (Deutero)Hydrodefluorination. Angew Chem Int Ed Engl 2023; 62:e202217244. [PMID: 36525004 DOI: 10.1002/anie.202217244] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
(Deuterium-labeled) CF2 H- and CFH2 -moieties are of high interest in drug discovery. The high demand for the incorporation of these fluoroalkyl moieties into molecular structures has witnessed significant synthetic progress, particularly in the (deutero)hydrodefluorination of CF3 -containing compounds. However, the controllable replacement of fluorine atoms while maintaining high chemoselectivity remains challenging. Herein, we describe the development of a selective (deutero)hydrodefluorination reaction via electrolysis. The reaction exhibits a remarkable chemoselectivity control, which is enabled by the addition of different organoboron sources. The procedure is operationally simple and scalable, and provides access in one step to high-value building blocks for application in medicinal chemistry. Furthermore, density functional theory (DFT) calculations have been carried out to investigate the reaction mechanism and to rationalize the chemoselectivity observed.
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Affiliation(s)
- Zheng-Jia Shen
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Chen Zhu
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Xiao Zhang
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Chao Yang
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Magnus Rueping
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Lin Guo
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Wujiong Xia
- State Key Lab of Urban Water Resource and Environment, School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.,School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, China
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11
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Liu A, Ni C, Xie Q, Hu J. Transition-Metal-Free Controllable Single and Double Difluoromethylene Formal Insertions into C-H Bonds of Aldehydes with TMSCF 2 Br. Angew Chem Int Ed Engl 2023; 62:e202217088. [PMID: 36517973 DOI: 10.1002/anie.202217088] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
We have developed a new strategy for controllable single and double difluoromethylene (CF2 ) formal insertions into C-H bonds of aldehydes with nearly full selectivity under transition-metal-free conditions. The key to the success of controllable CF2 insertions lies in the well-defined formation of 2,2-difluoroenolsilyl ether and 2,2,3,3-tetrafluorocyclopropanolsilyl ether intermediates using difluorocarbene reagent TMSCF2 Br (TMS=trimethylsilyl). These two intermediates can react with various electrophiles including proton sources and various halogenation reagents, allowing for the access to diverse arrays of ketones containing difluoromethylene (CF2 ) and tetrafluoroethylene (CF2 CF2 ) units. The first synthesis of relatively stable 2,2,3,3-tetrafluorocyclopropanolsilyl ethers has been achieved, which offers a new platform to explore other unknown chemical space.
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Affiliation(s)
- An Liu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Chuanfa Ni
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Qiqiang Xie
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Jinbo Hu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
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12
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Box JR, Avanthay ME, Poole DL, Lennox AJJ. Electronically Ambivalent Hydrodefluorination of Aryl‐CF 3 groups enabled by Electrochemical Deep‐Reduction on a Ni Cathode. Angew Chem Int Ed Engl 2023; 62:e202218195. [PMID: 36705627 PMCID: PMC10946569 DOI: 10.1002/anie.202218195] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/27/2023] [Accepted: 01/27/2023] [Indexed: 01/28/2023]
Abstract
We report a general procedure for the direct mono- and di-hydrodefluorination of ArCF3 compounds. Exploiting the tunability of electrochemistry and the selectivity enabled by a Ni cathode, the deep reduction garners high selectivity with good to excellent yields up to gram scale. The late-stage peripheral editing of CF3 feedstocks to construct fluoromethyl moieties will aid the rapid diversification of lead-compounds and compound libraries.
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Affiliation(s)
- John R. Box
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | | | - Darren L. Poole
- Discovery High-Throughput ChemistryMedicinal ChemistryGSK Medicines Research CentreStevenageSG1 2NYUK
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13
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He T, Liang C, Huang S. Cobalt-electrocatalytic C-H hydroxyalkylation of N-heteroarenes with trifluoromethyl ketones. Chem Sci 2022; 14:143-148. [PMID: 36605737 PMCID: PMC9769098 DOI: 10.1039/d2sc05198b] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/21/2022] [Indexed: 11/23/2022] Open
Abstract
Trifluoromethyl carbinols and N-heteroarenes are both prevalent in bioactive molecules. However, access to high-value pharmacophores combining these two functional groups still remains a challenge. Herein, we report an electro-chemical redox-neutral coupling for the synthesis of N-heteroaryl trifluoromethyl carbinols from readily available N-heteroarenes and trifluoromethyl ketones. The reaction starts with reversing the polarity of ketones to nucleophilic ketyl radicals through an electrocatalytic proton-coupled electron transfer (PCET), followed by radical addition to heteroarenes and rearomatization to afford tertiary alcohol products. Importantly, the merging of paired electrolysis and cobalt catalysis is crucial to this regioselective C-H hydroxyalkylation of heteroarenes, and thus avoids several known competing pathways including the spin-center shift (SCS) process. Collectively, this protocol provides straightforward access to heteroaryl trifluoromethyl carbinols, featuring ideal atom economy, excellent regioselectivity, and paired redox-neutral electrolysis.
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Affiliation(s)
- Tianyu He
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry UniversityNanjing 210037China
| | - Chaoqiang Liang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry UniversityNanjing 210037China
| | - Shenlin Huang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry UniversityNanjing 210037China
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14
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Recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.01.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Abstract
Fluorinated organic compounds are common among pharmaceuticals, agrochemicals and materials. The significant strength of the C-F bond results in chemical inertness that, depending on the context, is beneficial, problematic or simply a formidable synthetic challenge. Electrosynthesis is a rapidly expanding methodology that can enable new reactivity and selectivity for cleavage and formation of chemical bonds. Here, a comprehensive overview of synthetically relevant electrochemically driven protocols for C-F bond activation and functionalization is presented, including photoelectrochemical strategies.
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Affiliation(s)
- Johannes L Röckl
- Department of Chemistry, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
| | | | - Helena Lundberg
- Department of Chemistry, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
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16
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Kim S, Hwang KH, Park HG, Kwak J, Lee H, Kim H. Radical hydrodifluoromethylation of unsaturated C-C bonds via an electroreductively triggered two-pronged approach. Commun Chem 2022; 5:96. [PMID: 36697867 PMCID: PMC9814520 DOI: 10.1038/s42004-022-00697-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 06/27/2022] [Indexed: 01/28/2023] Open
Abstract
Due to its superior ability in controlling pharmaceutical activity, the installation of difluoromethyl (CF2H) functionality into organic molecules has been an area of intensive research. In this context, difluoromethylation of C-C π bonds mediated by a CF2H radical have been pursued as a central strategy to grant access to difluoromethylated hydrocarbons. However, early precedents necessitate the generation of oxidative chemical species that can limit the generality and utility of the reaction. We report here the successful implementation of radical hydrodifluoromethylation of unsaturated C-C bonds via an electroreductively triggered two-pronged approach. Preliminary mechanistic investigations suggest that the key distinction of the present strategy originates from the reconciliation of multiple redox processes under highly reducing electrochemical conditions. The reaction conditions can be chosen based on the electronic properties of the alkenes of interest, highlighting the hydrodifluoromethylation of both unactivated and activated alkenes. Notably, the reaction delivers geminal (bis)difluoromethylated products from alkynes in a single step by consecutive hydrodifluoromethylation, granting access to an underutilized 1,1,3,3-tetrafluoropropan-2-yl functional group. The late-stage hydrodifluoromethylation of densely functionalized pharmaceutical agents is also presented.
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Affiliation(s)
- Seonyoung Kim
- grid.255649.90000 0001 2171 7754Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, 03760 Republic of Korea
| | - Keon Ha Hwang
- grid.29869.3c0000 0001 2296 8192Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114 Republic of Korea ,grid.254230.20000 0001 0722 6377Graduate School of New Drug Discovery and Development, Chungnam University, Daejeon, 34134 Republic of Korea
| | - Hyeong Gyu Park
- grid.29869.3c0000 0001 2296 8192Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114 Republic of Korea ,grid.254230.20000 0001 0722 6377Graduate School of New Drug Discovery and Development, Chungnam University, Daejeon, 34134 Republic of Korea
| | - Jaesung Kwak
- grid.29869.3c0000 0001 2296 8192Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114 Republic of Korea
| | - Hyuk Lee
- grid.29869.3c0000 0001 2296 8192Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114 Republic of Korea
| | - Hyunwoo Kim
- grid.49100.3c0000 0001 0742 4007Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
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17
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Yan G. Photochemical and Electrochemical Strategies for Hydrodefluorination of Fluorinated Organic Compounds. Chemistry 2022; 28:e202200231. [PMID: 35301767 DOI: 10.1002/chem.202200231] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Indexed: 12/20/2022]
Abstract
Hydrodefluorination (HDF) is a very important fundamental transformation for conversion of the C-F bond into the C-H bond in organic synthesis. In the past decade, much progress has been achieved with HDF through the utility of low-valent metals, transition-metal complexes and main-group Lewis acids. Recently, novel methods have been introduced for this purpose through photo- and electrochemical pathways, which are of great significance, due to their considerable environmental and economical advantages. This Review highlights the HDF of fluorinated organic compounds (FOCs) through photo- and electrochemical strategies, along with mechanistic insights.
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Affiliation(s)
- Guobing Yan
- Department of Chemistry, College of Jiyang, Zhejiang A&F University, Zhuji, Zhejiang, 311800, P. R. China
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18
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Ghosh S, Qu Z, Pradhan S, Ghosh A, Grimme S, Chatterjee I. HFIP‐Assisted Single C−F Bond Activation of Trifluoromethyl Ketones using Visible‐Light Photoredox Catalysis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Soumen Ghosh
- Department of Chemistry Indian Institute of Technology Ropar Nangal Road Rupnagar Punjab 140001 India
| | - Zheng‐Wang Qu
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Suman Pradhan
- Department of Chemistry Indian Institute of Technology Ropar Nangal Road Rupnagar Punjab 140001 India
| | - Avisek Ghosh
- Department of Chemistry Indian Institute of Technology Ropar Nangal Road Rupnagar Punjab 140001 India
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry Institut für Physikalische und Theoretische Chemie Rheinische Friedrich-Wilhelms-Universität Bonn Beringstrasse 4 53115 Bonn Germany
| | - Indranil Chatterjee
- Department of Chemistry Indian Institute of Technology Ropar Nangal Road Rupnagar Punjab 140001 India
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19
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Zhang X, Zhang X, Song Q, Sivaguru P, Wang Z, Zanoni G, Bi X. A Carbene Strategy for Progressive (Deutero)Hydrodefluorination of Fluoroalkyl Ketones. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202116190] [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)
- Xiaolong Zhang
- Department of Chemistry Northeast Normal University Changchun 130024 China
| | - Xinyu Zhang
- Department of Chemistry Northeast Normal University Changchun 130024 China
| | - Qingmin Song
- Department of Chemistry Northeast Normal University Changchun 130024 China
| | | | - Zikun Wang
- Department of Chemistry Northeast Normal University Changchun 130024 China
| | - Giuseppe Zanoni
- Department of Chemistry University of Pavia Viale Taramelli 12 27100 Pavia Italy
| | - Xihe Bi
- Department of Chemistry Northeast Normal University Changchun 130024 China
- State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China
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20
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Wang Z, Sun Y, Shen LY, Yang WC, Meng F, Li P. Photochemical and electrochemical strategies in C–F bond activation and functionalization. Org Chem Front 2022. [DOI: 10.1039/d1qo01512e] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recent advances in photochemical or electrochemical C–F bond activation and functionalization have been summarized and discussed.
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Affiliation(s)
- Zhanghong Wang
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, PR China
| | - Yu Sun
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Liu-Yu Shen
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Wen-Chao Yang
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Fei Meng
- School of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Pinhua Li
- Anhui Laboratory of Clean Catalytic Engineering, Anhui Laboratory of Functional Complexes for Materials Chemistry and Application, College of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, Anhui 241000, P. R. of China
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21
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Yan G, Gong X, Zhou Q. Recent advances in C-F bond activation of trifluoromethylated carbonyl compounds and derivatives. Org Biomol Chem 2022; 20:5365-5376. [DOI: 10.1039/d2ob00795a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The selective activation of the inert C-F bonds is one of the most challenging topics in modern organic chemistry. Trifluoromethylketones represent a class of versatile building blocks, which are inexpensive...
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22
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Zhang X, Zhang X, Song Q, Sivaguru P, Wang Z, Zanoni G, Bi X. A Carbene Strategy for Progressive (Deutero)Hydrodefluorination of Fluoroalkyl Ketones. Angew Chem Int Ed Engl 2021; 61:e202116190. [PMID: 34889004 DOI: 10.1002/anie.202116190] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Indexed: 12/29/2022]
Abstract
Hydrodefluorination is one of the most promising chemical strategies to degrade perfluorochemicals into partially fluorinated compounds. However, controlled progressive hydrodefluorination remains a significant challenge, owing to the decrease in the strength of C-F bonds along with the defluorination. Here we describe a carbene strategy for the sequential (deutero)hydrodefluorination of perfluoroalkyl ketones under rhodium catalysis, allowing for the controllable preparation of difluoroalkyl- and monofluoroalkyl ketones from aryl- and even alkyl-substituted perfluoro-alkyl ketones in high yield with excellent functional group tolerance. The reaction mechanism and the origin of the intriguing chemoselectivity of the reaction were rationalized by density functional theory (DFT) calculations.
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Affiliation(s)
- Xiaolong Zhang
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China
| | - Xinyu Zhang
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China
| | - Qingmin Song
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China
| | | | - Zikun Wang
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China
| | - Giuseppe Zanoni
- Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100, Pavia, Italy
| | - Xihe Bi
- Department of Chemistry, Northeast Normal University, Changchun, 130024, China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
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23
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Ghosh S, Qu ZW, Pradhan S, Ghosh A, Grimme S, Chatterjee I. HFIP-Assisted Single C-F Bond Activation of Trifluoromethyl Ketones using Visible-Light Photoredox Catalysis. Angew Chem Int Ed Engl 2021; 61:e202115272. [PMID: 34821454 DOI: 10.1002/anie.202115272] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Indexed: 11/07/2022]
Abstract
A visible light photoredox catalytic method for the selective cleavage of single strong C-F bond in trifluoromethyl ketones is reported. Single electron reduction of trifluoromethyl ketones generates difluoromethyl radicals which can be engaged in intermolecular C-C bond formation with N-methyl-N-arylmethacrylamides to furnish fluorine-containing oxindole derivatives in good yields. The reaction shows excellent chemoselectivity with good functional group tolerance under mild conditions. 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) as a solvent plays a critical role for the selective single C-F bond cleavage. High-level DFT calculations are depicted to shed light on the mechanism.
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Affiliation(s)
- Soumen Ghosh
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Suman Pradhan
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
| | - Avisek Ghosh
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany
| | - Indranil Chatterjee
- Department of Chemistry, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab, 140001, India
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24
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Ispizua-Rodriguez X, Munoz SB, Krishnamurti V, Mathew T, Prakash GKS. Direct Synthesis of Tri-/Difluoromethyl Ketones from Carboxylic Acids by Cross-Coupling with Acyloxyphosphonium Ions. Chemistry 2021; 27:15908-15913. [PMID: 34469605 DOI: 10.1002/chem.202102854] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Indexed: 11/09/2022]
Abstract
A simple and straightforward approach to the synthesis of trifluoromethyl and difluoromethyl ketones from widely available carboxylic acids is disclosed. The transformation utilizes an acyloxyphosphonium ion as the active electrophile, conveniently generated in situ from the carboxylic acid substrate by using commodity chemicals. The utility of the reaction system is exemplified by its chemoselectivity, with tolerance to a variety of important functional groups. The late-stage functionalization of carboxylic acid active pharmaceutical ingredients and pharmaceutically relevant compounds is also discussed.
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Affiliation(s)
- Xanath Ispizua-Rodriguez
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, 837 Bloom Walk, Los Angeles, CA-90089-1661, USA
| | - Socrates B Munoz
- Department of Chemistry, Kansas State University, 322 CBC Bldg, Manhattan, KS66506-0401, USA
| | - Vinayak Krishnamurti
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, 837 Bloom Walk, Los Angeles, CA-90089-1661, USA
| | - Thomas Mathew
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, 837 Bloom Walk, Los Angeles, CA-90089-1661, USA
| | - G K S Prakash
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, 837 Bloom Walk, Los Angeles, CA-90089-1661, USA
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25
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An X, Feng Z, Huang L, Yang Y, Liu Z. Recent Advances in the Single C—F Bond Cleavage Reactions of Trifluoromethylarenes. CHINESE J ORG CHEM 2021. [DOI: 10.6023/cjoc202110037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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