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Patel C, André-Joyaux E, Leitch JA, de Irujo-Labalde XM, Ibba F, Struijs J, Ellwanger MA, Paton R, Browne DL, Pupo G, Aldridge S, Hayward MA, Gouverneur V. Fluorochemicals from fluorspar via a phosphate-enabled mechanochemical process that bypasses HF. Science 2023; 381:302-306. [PMID: 37471551 DOI: 10.1126/science.adi1557] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/14/2023] [Indexed: 07/22/2023]
Abstract
All fluorochemicals-including elemental fluorine and nucleophilic, electrophilic, and radical fluorinating reagents-are prepared from hydrogen fluoride (HF). This highly toxic and corrosive gas is produced by the reaction of acid-grade fluorspar (>97% CaF2) with sulfuric acid under harsh conditions. The use of fluorspar to produce fluorochemicals via a process that bypasses HF is highly desirable but remains an unsolved problem because of the prohibitive insolubility of CaF2. Inspired by calcium phosphate biomineralization, we herein disclose a protocol of treating acid-grade fluorspar with dipotassium hydrogen phosphate (K2HPO4) under mechanochemical conditions. The process affords a solid composed of crystalline K3(HPO4)F and K2-xCay(PO3F)a(PO4)b, which is found suitable for forging sulfur-fluorine and carbon-fluorine bonds.
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Affiliation(s)
- Calum Patel
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
| | - Emy André-Joyaux
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
| | - Jamie A Leitch
- Department of Pharmaceutical and Biological Chemistry, University College London School of Pharmacy, London W1CN 1AX, UK
- FluoRok Ltd., Begbroke Science Park, Begbroke Hill, Woodstock Road, Begbroke OX5 1PF, UK
| | | | - Francesco Ibba
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
- FluoRok Ltd., Begbroke Science Park, Begbroke Hill, Woodstock Road, Begbroke OX5 1PF, UK
| | - Job Struijs
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
| | | | - Robert Paton
- Department of Chemistry, Colorado State University, Fort Collins, CO 80528, USA
| | - Duncan L Browne
- Department of Pharmaceutical and Biological Chemistry, University College London School of Pharmacy, London W1CN 1AX, UK
| | - Gabriele Pupo
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
- FluoRok Ltd., Begbroke Science Park, Begbroke Hill, Woodstock Road, Begbroke OX5 1PF, UK
| | - Simon Aldridge
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, UK
| | - Michael A Hayward
- Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, UK
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2
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Muto R, Nagata K, Nakazumi Y, Nakamura K, Ueno S. Palladium-Catalyzed para-Selective Allylation of 1-(Cyanomethyl)arenes with Allyl Acetates. Org Lett 2023; 25:2108-2112. [PMID: 36940090 DOI: 10.1021/acs.orglett.3c00534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
The Pd/PMe3-catalyzed allylation of 1-(cyanomethyl)naphthalenes with allyl acetates proved to be para- rather than α-regioselective. This reaction is thought to proceed through ligand attack of the para-carbon in the arenes, electronically enriched by a cyano-stabilized α-carbanion, to the (π-allyl)palladium and a 1,5-hydrogen shift of the para-hydrogen from the dearomatized intermediate.
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Affiliation(s)
- Rina Muto
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
| | - Kenji Nagata
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
| | - Yoshiki Nakazumi
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
| | - Kaho Nakamura
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
| | - Satoshi Ueno
- Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
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3
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Boldrini C, Reis MC, Harutyunyan SR. Electrophilic Trapping of Semibenzenes. J Org Chem 2022; 87:12772-12782. [PMID: 36095222 PMCID: PMC9552181 DOI: 10.1021/acs.joc.2c01331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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In this work, we
demonstrate how allylative dearomatization of
benzyl chlorides can provide direct access to a variety of semibenzenes.
These scaffolds behave as highly reactive nucleophiles in the presence
of carbocations. In addition, semibenzenes are susceptible to intramolecular
rearrangements rendering a broad scope of functionalized arenes. An
analysis of this new reactivity is reported, as well as the rationale
behind the observed intramolecular reorganizations.
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Affiliation(s)
- Cosimo Boldrini
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Marta Castiñeira Reis
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Syuzanna R Harutyunyan
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Wang Y, Zhang S, Feng X, Yu X, Yamaguchi M, Bao M. Palladium-Catalyzed Para-C-H Bond Amination of 2-Aryl Chloromethylbenzenes. J Org Chem 2022; 87:10531-10538. [PMID: 35899766 DOI: 10.1021/acs.joc.2c01233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Palladium-catalyzed para-C-H bond amination of 2-aryl chloromethylbenzenes is described for the first time. The reactions of 2-aryl chloromethylbenzenes with cyclic amines proceeded smoothly in the presence of Pd(acac)2, tri(2-furyl)phosphine, and NaH in tetrahydrofuran at 40 °C to provide para-C-H bond aminated products in satisfactory to high yields with acceptable regioselectivity in most cases. The electronic property of the substituents linked to the benzene rings did not significantly influence the reactivity of the 2-aryl chloromethylbenzene substrates and the reaction regioselectivity.
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Affiliation(s)
- Yingqi Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Sheng Zhang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Xiujuan Feng
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Xiaoqiang Yu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Masahiko Yamaguchi
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Ming Bao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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