1
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Patrick SL, Bull JA, Miller PW, Crimmin MR. A Continuous Flow Process for the Defluorosilylation of HFC-23 and HFO-1234yf. Org Lett 2024; 26:8605-8609. [PMID: 39352945 DOI: 10.1021/acs.orglett.4c03274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2024]
Abstract
A continuous flow process has been developed for the defluorosilylation of trifluoromethane (HFC-23) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) through reaction with lithium silanide reagents under inert conditions. Design of experiment optimization improved process conditions, including productivity, yields, reduction of solvent use, and gas destruction. The small chain fluorinated organosilane products R3SiCF2H and R3SiCH2C(F)═CF2 were competent nucleophiles in the fluoride-catalyzed difluoromethylation of aldehydes, and trifluoroallylation of aldehydes, ketones, and imines.
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Affiliation(s)
- Sarah L Patrick
- Department of Chemistry, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, U.K
| | - James A Bull
- Department of Chemistry, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, U.K
| | - Philip W Miller
- Department of Chemistry, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, U.K
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, U.K
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2
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Sheldon DJ, Crimmin MR. Repurposing of F-gases: challenges and opportunities in fluorine chemistry. Chem Soc Rev 2022; 51:4977-4995. [PMID: 35616085 PMCID: PMC9207706 DOI: 10.1039/d1cs01072g] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Indexed: 11/24/2022]
Abstract
Fluorinated gases (F-gases) are routinely employed as refrigerants, blowing agents, and electrical insulators. These volatile compounds are potent greenhouse gases and consequently their release to the environment creates a significant contribution to global warming. This review article seeks to summarise: (i) the current applications of F-gases, (ii) the environmental issues caused by F-gases, (iii) current methods of destruction of F-gases and (iv) recent work in the field towards the chemical repurposing of F-gases. There is a great opportunity to tackle the environmental and sustainability issues created by F-gases by developing reactions that repurpose these molecules.
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Affiliation(s)
- Daniel J Sheldon
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
| | - Mark R Crimmin
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, Shepherds Bush, London, W12 0BZ, UK.
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3
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Zhou J, Zhao Z, Shibata N. Silylboronate-Mediated Defluorosilylation of Aryl Fluorides with or without Ni-Catalyst. Front Chem 2021; 9:771473. [PMID: 34760872 PMCID: PMC8573161 DOI: 10.3389/fchem.2021.771473] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
The defluorosilylation of aryl fluorides to access aryl silanes was achieved under transition-metal-free conditions via an inert C-F bond activation. The defluorosilylation, mediated by silylboronates and KOtBu, proceeded smoothly at room temperature to afford various aryl silanes in good yields. Although a comparative experiment indicated that Ni catalyst facilitated this transformation more efficiently, the transition-metal-free protocol is advantageous from a green chemistry perspective.
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Affiliation(s)
- Jun Zhou
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Nagoya, Japan
| | - Zhengyu Zhao
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Nagoya, Japan
| | - Norio Shibata
- Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology, Nagoya, Japan.,Institute of Advanced Fluorine-Containing Materials, Zhejiang Normal University, Jinhua, China
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Burton KI, Elser I, Waked AE, Wagener T, Andrews RJ, Glorius F, Stephan DW. Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity. Chemistry 2021; 27:11730-11737. [PMID: 34107119 DOI: 10.1002/chem.202101534] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Indexed: 01/06/2023]
Abstract
The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10 H6 R2 N2 CH2 CH2 ]2+ (R=H [1 a]2+ , Me [1 f]2+ , tBu [1 g]2+ ), and [C12 H4 R4 N2 CH2 CH2 ]2+ (R=H [2 a]2+ , Me [2 b]2+ ) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3 (C-F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3 )3 C6 H9 . The dications are shown to act as hydride acceptors with the isolation of neutral species C16 H14 N2 (3 a) and C16 H10 Me4 N2 (3 b) and monocationic species [C14 H13 N2 ]+ ([4 a]+ ) and [C18 H21 N2 ]+ ([4 b]+ ). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.
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Affiliation(s)
- Katherine I Burton
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Iris Elser
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Alexander E Waked
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Tobias Wagener
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Ryan J Andrews
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Douglas W Stephan
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
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5
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Sheldon DJ, Crimmin MR. Complete deconstruction of SF 6 by an aluminium(I) compound. Chem Commun (Camb) 2021; 57:7096-7099. [PMID: 34159971 PMCID: PMC8291285 DOI: 10.1039/d1cc02838c] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The room-temperature activation of SF6, a potent greenhouse gas, is reported using a monovalent aluminium(i) reagent to form well-defined aluminium(iii) fluoride and aluminium(iii) sulfide products. New reactions have been developed to utilise the aluminium(iii) fluoride and aluminium(iii) sulfide as a nucleophilic source of F− and S2− for a range of electrophiles. The overall reaction sequence results in the net transfer of fluorine or sulfur atoms from an environmentally detrimental gas to useful organic products. The room-temperature activation of SF6, a potent greenhouse gas, is reported using a monovalent aluminium(i) reagent to form well-defined aluminium(iii) fluoride and aluminium(iii) sulfide products.![]()
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Affiliation(s)
- Daniel J Sheldon
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, London, W12 0BZ, UK.
| | - Mark R Crimmin
- Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, London, W12 0BZ, UK.
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Achternbosch M, Brieger L, Strohmann C. Influence Of Lithium Coordinating Additives On The Structure Of Phenyldimethylsilyllithium. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202100031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Moritz Achternbosch
- Fakultät für Chemie und Chemische Biologie Technische Universität Dortmund Otto-Hahn-Str. 6 44227 Dortmund
| | - Lukas Brieger
- Fakultät für Chemie und Chemische Biologie Technische Universität Dortmund Otto-Hahn-Str. 6 44227 Dortmund
| | - Carsten Strohmann
- Fakultät für Chemie und Chemische Biologie Technische Universität Dortmund Otto-Hahn-Str. 6 44227 Dortmund
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Yan G, Qiu K, Guo M. Recent advance in the C–F bond functionalization of trifluoromethyl-containing compounds. Org Chem Front 2021. [DOI: 10.1039/d1qo00037c] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The C–F bond is the strongest single bond in organic compounds.
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Affiliation(s)
- Guobing Yan
- College of Jiyang
- Zhejiang A&F University
- Zhuji 311800
- China
- College of Science
| | - Kaiying Qiu
- Department of Chemistry
- Lishui University
- Lishui 323000
- China
| | - Ming Guo
- College of Jiyang
- Zhejiang A&F University
- Zhuji 311800
- China
- College of Science
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