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Yu Q, Zhou D, Ma J, Song C. Decarboxylative Nucleophilic Fluorination of Aliphatic Carboxylic Acids. Org Lett 2024; 26:4257-4261. [PMID: 38738813 DOI: 10.1021/acs.orglett.4c01185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Herein, we present a decarboxylative nucleophilic fluorination of carboxylic acids with a silver catalyst. This strategy enables the synthesis of a myriad of diverse and valuable fluorinated motifs under mild conditions, demonstrating good functional-group tolerance and utility in late-stage functionalization. In contrast to traditional electrophilic fluorination, this nucleophilic method utilizes a more readily available nucleophilic fluorinating reagent, providing substantial advantages in terms of cost efficiency, broad substrate scope, and functional-group compatibility.
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Affiliation(s)
- Qian Yu
- College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Donglin Zhou
- College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Junjun Ma
- College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Chunlan Song
- College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
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2
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Kiaku C, Martinage D, Sicim Y, Leech MC, Walsh JM, Poole DL, Mason J, Goodall ICA, Devo P, Lam K. eFluorination of Activated Alcohols Using Collidinium Tetrafluoroborate. Org Lett 2024; 26:2697-2701. [PMID: 37204455 DOI: 10.1021/acs.orglett.3c00976] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Tertiary C-F bonds are important structural designs; however, they suffer from challenging synthesis. Current methodologies use corrosive amine-HF salts or expensive and hazardous catalysts and reagents. Our group recently introduced collidinium tetrafluoroborate as an efficient fluorinating agent for anodic decarboxyfluorination reactions. Nevertheless, tertiary carboxylic acids are less readily available and more challenging to prepare than their alcohol analogues. Herein we report a practical, mild, and cheap electrochemical method to achieve deoxyfluorination of hindered carbon centers.
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Affiliation(s)
- Cyrille Kiaku
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Dorian Martinage
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Yasemin Sicim
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Matthew C Leech
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Jamie M Walsh
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Darren L Poole
- Discovery High-Throughput Chemistry, Medicinal Chemistry, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, Hertfordshire, U.K
| | - Joseph Mason
- Discovery High-Throughput Chemistry, Medicinal Chemistry, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage SG1 2NY, Hertfordshire, U.K
| | - Iain C A Goodall
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Perry Devo
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Kevin Lam
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
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3
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Darzina M, Jirgensons A. Electrochemical Formation of Oxazolines by 1,3-Oxyfluorination of Non-activated Cyclopropanes. Org Lett 2024; 26:2158-2162. [PMID: 38456832 DOI: 10.1021/acs.orglett.4c00143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The C-C bond in non-activated cyclopropanes can be intramolecularly cleaved with an electrochemically generated amidyl radical forming oxazolines. In the presence of TBABF4, this provides 1,3-oxyfluorination products. C-C bond cleavage of cyclopropane proceeds with inversion of the configuration, suggesting an intramolecular homolytic substitution (SHi) mechanism. The performance of TBABF4 as an efficient fluoride source was explained by accumulation of the BF4- anion at the anode surface, at which a carbocation is formed by the oxidation of the C-centered radical.
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Affiliation(s)
- Madara Darzina
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV-1006 Riga, Latvia
| | - Aigars Jirgensons
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV-1006 Riga, Latvia
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4
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Shibutani S, Nagao K, Ohmiya H. A Dual Cobalt and Photoredox Catalysis for Hydrohalogenation of Alkenes. J Am Chem Soc 2024; 146:4375-4379. [PMID: 38300804 DOI: 10.1021/jacs.3c10133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
We demonstrate hydrohalogenation of aliphatic alkenes with collidine·HX salts through dual photoredox/cobalt catalysis. The dual catalysis enables conversion of a proton and a halide anion from collidine·HX salt to a nucleophilic hydrogen radical equivalent and an electrophilic halogen radical equivalent and delivery of them to an alkene moiety. This protocol allows for introduction of fluorine, chlorine, bromine, or iodine atom to alkene, producing highly functionalized alkyl halides.
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Affiliation(s)
- Shotaro Shibutani
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Kazunori Nagao
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Hirohisa Ohmiya
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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5
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Atkins AP, Chaturvedi AK, Tate JA, Lennox AJJ. Pulsed electrolysis: enhancing primary benzylic C(sp 3)-H nucleophilic fluorination. Org Chem Front 2024; 11:802-808. [PMID: 38298566 PMCID: PMC10825853 DOI: 10.1039/d3qo01865b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/09/2023] [Indexed: 02/02/2024]
Abstract
Electrosynthesis is an efficient and powerful tool for the generation of elusive reactive intermediates. The application of alternative electrolysis waveforms provides a new level of control for dynamic redox environments. Herein, we demonstrate that pulsed electrolysis provides a favourable environment for the generation and fluorination of highly unstable primary benzylic cations from C(sp3)-H bonds. By introduction of a toff period, we propose this waveform modulates the electrical double layer to improve mass transport and limit over-oxidation.
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Affiliation(s)
- Alexander P Atkins
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
| | - Atul K Chaturvedi
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
| | - Joseph A Tate
- Jealott's Hill International Research Centre, Syngenta Jealott's Hill Bracknell RG426EY UK
| | - Alastair J J Lennox
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
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6
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Lee TC, Tong Y, Fu WC. Advances in Continuous Flow Fluorination Reactions. Chem Asian J 2023; 18:e202300723. [PMID: 37707985 DOI: 10.1002/asia.202300723] [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: 08/17/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/16/2023]
Abstract
Fluorination reactions are important in constructing organofluorine motifs, which contribute to favorable biological properties in pharmaceuticals and agrochemicals. However, fluorination reagents and reactions are associated with various problems, such as their hazardous nature, high exothermicity, and poor selectivity and scalability. Continuous flow has emerged as a transformative technology to provide many advantages relative to batch syntheses. This review article summarizes recent continuous flow techniques that address the limitations and challenges of fluorination reactions. Approaches based on different flow techniques are discussed, including gas-liquid reactions, packed-bed reactors, in-line purifications, streamlined multistep synthesis, large-scale reactions well as flow photoredox- and electrocatalysis.
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Affiliation(s)
- Tsz Chun Lee
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Yi Tong
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Wai Chung Fu
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
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7
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Garrido-Castro AF, Hioki Y, Kusumoto Y, Hayashi K, Griffin J, Harper KC, Kawamata Y, Baran PS. Scalable Electrochemical Decarboxylative Olefination Driven by Alternating Polarity. Angew Chem Int Ed Engl 2023; 62:e202309157. [PMID: 37656907 DOI: 10.1002/anie.202309157] [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: 06/28/2023] [Revised: 08/18/2023] [Accepted: 09/01/2023] [Indexed: 09/03/2023]
Abstract
A mild, scalable (kg) metal-free electrochemical decarboxylation of alkyl carboxylic acids to olefins is disclosed. Numerous applications are presented wherein this transformation can simplify alkene synthesis and provide alternative synthetic access to valuable olefins from simple carboxylic acid feedstocks. This robust method relies on alternating polarity to maintain the quality of the electrode surface and local pH, providing a deeper understanding of the Hofer-Moest process with unprecedented chemoselectivity.
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Affiliation(s)
- Alberto F Garrido-Castro
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093, Zürich, Switzerland
| | - Yuta Hioki
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Science and Innovation Center, Mitsubishi Chemical Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa 227-8502, Japan
| | - Yoshifumi Kusumoto
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Kyohei Hayashi
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Jeremy Griffin
- AbbVie Process Research and Development, 1401 North Sheridan Road, North Chicago, IL, 60064, USA
| | - Kaid C Harper
- AbbVie Process Research and Development, 1401 North Sheridan Road, North Chicago, IL, 60064, USA
| | - Yu Kawamata
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Phil S Baran
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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