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Sedikides AT, Lennox AJJ. Silver-Catalyzed ( Z)-β-Fluoro-vinyl Iodonium Salts from Alkynes: Efficient and Selective Syntheses of Z-Monofluoroalkenes. J Am Chem Soc 2024. [PMID: 38829699 DOI: 10.1021/jacs.4c03826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Monofluoroalkenes are stable and lipophilic amide bioisosteres used in medicinal chemistry. However, efficient and stereoselective methods for synthesizing Z-monofluoroalkenes are underdeveloped. We envisage (Z)-β-fluoro-vinyl iodonium salts (Z-FVIs) as coupling partners for the diverse and stereoselective synthesis of Z-monofluoroalkenes. Disclosed herein is the development and application of a silver(I)-catalyzed process for accessing a broad scope of (Z)-FVIs with exclusive Z-stereoselectivity and regioselectivity from alkynes in a single step. Experimental and computational studies provide insight into the mechanism of the catalytic cycle and the role of the silver(I) catalyst, and the reactivity of (Z)-FVIs is explored through several stereospecific derivatizations.
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Affiliation(s)
- Alexi T Sedikides
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Alastair J J Lennox
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
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2
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Farley SES, Mulryan D, Rekhroukh F, Phanopoulos A, Crimmin MR. Catalytic HF Shuttling between Fluoroalkanes and Alkynes. Angew Chem Int Ed Engl 2023:e202317550. [PMID: 38069591 DOI: 10.1002/anie.202317550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Indexed: 12/23/2023]
Abstract
In this paper, we report BF3 ⋅ OEt2 as a catalyst to shuttle equivalents of HF from a fluoroalkane to an alkyne. Reactions of terminal and internal aliphatic alkynes led to formation of difluoroalkane products, while diarylalkynes can be selectively converted into fluoroalkenes. The method tolerates numerous sensitive functional groups including halogen, protected amine, ester and thiophene substituents. Mechanistic studies (DFT, probe experiments) suggest the catalyst is involved in both the defluorination and fluorination steps, with BF3 acting as a Lewis acid and OEt2 a weak Lewis base that mediates proton transfer. In certain cases, the interconversion of fluoroalkene and difluoroalkane products was found to be reversible. The new catalytic system was applied to demonstrate proof-of-concept recycling of poly(vinylidene difluoride).
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Affiliation(s)
- Shannon E S Farley
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Daniel Mulryan
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Feriel Rekhroukh
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Andreas Phanopoulos
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
| | - Mark R Crimmin
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK
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3
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Gauthier R, Paquin JF. Hydrofluorination of Alkynes: From (E) to (Z). Chemistry 2023; 29:e202301896. [PMID: 37458694 DOI: 10.1002/chem.202301896] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Indexed: 09/09/2023]
Abstract
The hydrofluorination of alkynes is an efficient synthetic route to monofluoroalkenes or difluoroalkanes. Both fluorinated motifs have found applications in medicinal chemistry and beyond. This review explores the recent advances in the hydrofluorination of diverse alkynes through various activation methods, from classical coinage metal catalysis to metal-free conditions. The range of alkynes goes from the simplest unactivated alkynes to activated ones (ynones and derivatives, ynamides, alkynyl sulfides and sulfones as much as haloalkynes). Regio- and stereoselective methods exists, but there is still room for improvement depending on the type of alkyne.
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Affiliation(s)
- Raphaël Gauthier
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada
| | - Jean-François Paquin
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada
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4
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Heinekamp C, Buzanich AG, Ahrens M, Braun T, Emmerling F. An amorphous Lewis-acidic zirconium chlorofluoride as HF shuttle: C-F bond activation and formation. Chem Commun (Camb) 2023; 59:11224-11227. [PMID: 37655607 DOI: 10.1039/d3cc03164k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
An exceptional HF transfer reaction by C-F bond activation of fluoropentane and a subsequent hydrofluorination of alkynes at room temperature is reported. An amorphous Lewis-acidic Zr chlorofluoride serves as heterogeneous catalyst, which is characterised by an eightfold coordination environment at Zr including chlorine atoms. The studies are seminal in establishing sustainable fluorine chemistry.
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Affiliation(s)
- Christian Heinekamp
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Ana Guilherme Buzanich
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
| | - Mike Ahrens
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Thomas Braun
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
| | - Franziska Emmerling
- Department Materials Chemistry, Federal Institute for Material Research and Testing, Richard-Willstätter-Straße 11, 12489 Berlin, Germany.
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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5
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Dehydrofluorination reactions at Lewis acidic ACF in the presence of HSnBu3. J Fluor Chem 2022. [DOI: 10.1016/j.jfluchem.2022.110046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Pan X, Talavera M, Scholz G, Braun T. Chlorodefluorination of Fluoromethanes and Fluoroolefins at a Lewis Acidic Aluminum Fluoride. ChemCatChem 2022. [DOI: 10.1002/cctc.202200029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Xinzi Pan
- Humboldt-Universitat zu Berlin Department of Chemistry GERMANY
| | - Maria Talavera
- Humboldt-Universitat zu Berlin Department of Chemistry GERMANY
| | - Gudrun Scholz
- Humboldt-Universitat zu Berlin Department of Chemistry GERMANY
| | - Thomas Braun
- Humboldt University Chemistry Brook-Taylor Str. 2 12489 Berlin GERMANY
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7
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Deng Y, Liang Z, Lu X, Chen D, Li Z, Wang F. The degradation mechanisms of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) by different chemical methods: A critical review. CHEMOSPHERE 2021; 283:131168. [PMID: 34182635 DOI: 10.1016/j.chemosphere.2021.131168] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are a class of artificial compounds comprised of a perfluoroalkyl main chain and a terminal functional group. With them being applied in a wide range of applications, PFASs have drawn increasing regulatory attention and research interests on their reductions and treatments due to their harmful effects on environment and human beings. Among numerous studies, chemical treatments (e.g., photochemical, electrochemical, and thermal technologies) have been proved to be important methods to degradation PFASs. However, the pathways and mechanisms for the degradation of PFASs through these chemical methods still have not been well documented. This article therefore provides a comprehensive review on the degradation mechanisms of two important PFASs (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)) with photochemical, electrochemical and thermal methods. Different decomposition mechanisms of PFOA and PFOS are reviewed and discussed. Overall, the degradation pathways of PFASs are associated closely with their head groups and chain lengths, and H/F exchange and chain shortening were found to be predominant degradation mechanisms. The clear study on the degradation mechanisms of PFOA and PFOS should be very useful for the complete degradation or mineralization of PFASs in the future.
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Affiliation(s)
- Yun Deng
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zhihong Liang
- The Pearl River Water Resources Research Institute, Guangzhou, Guangdong, 510611, China
| | - Xingwen Lu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zhe Li
- School of Engineering and Materials Science, Faculty of Science and Engineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Fei Wang
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
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Kervarec M, Kemnitz E, Scholz G, Rudić S, Braun T, Jäger C, Michalchuk AAL, Emmerling F. A HF Loaded Lewis-Acidic Aluminium Chlorofluoride for Hydrofluorination Reactions. Chemistry 2020; 26:7314-7322. [PMID: 32315479 PMCID: PMC7318592 DOI: 10.1002/chem.202001627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Indexed: 12/14/2022]
Abstract
The very strong Lewis acid aluminium chlorofluoride (ACF) was loaded with anhydrous HF. The interaction between the surface of the catalyst and HF was investigated using a variety of characterization methods, which revealed the formation of polyfluorides. Moreover, the reactivity of the HF-loaded ACF towards the hydrofluorination of alkynes was studied.
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Affiliation(s)
| | - Erhard Kemnitz
- Department of ChemistryHumboldt-Universität zu BerlinBrook-Taylor-Straße 212489BerlinGermany
| | - Gudrun Scholz
- Department of ChemistryHumboldt-Universität zu BerlinBrook-Taylor-Straße 212489BerlinGermany
| | - Svemir Rudić
- ISIS Neutron and Muon Source, STFCRutherford Appleton LaboratoryChilton, DidcotUK
| | - Thomas Braun
- Department of ChemistryHumboldt-Universität zu BerlinBrook-Taylor-Straße 212489BerlinGermany
| | - Christian Jäger
- BAM Federal Institute for Materials Research and TestingRichard-Willstätter-Straße12489BerlinGermany
| | - Adam A. L. Michalchuk
- BAM Federal Institute for Materials Research and TestingRichard-Willstätter-Straße12489BerlinGermany
| | - Franziska Emmerling
- BAM Federal Institute for Materials Research and TestingRichard-Willstätter-Straße12489BerlinGermany
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