Metallomimetic C-F Activation Catalysis by Simple Phosphines

John Martin Slattery*, Sara Bonfante, Jason Martin Lynam*, Antoine Simonneau*, Christian Lorber*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Delivering metallomimetic reactivity from simple p-block compounds is highly desirable in the search to replace expensive, scarce precious metals by cheap and abundant elements in catalysis. This contribution demonstrates that metallomimetic catalysis, involving facile redox cycling between the P(III) and P(V) oxidation states, is possible using only simple, cheap, and readily available trialkylphosphines without the need to enforce unusual geometries at phosphorus or use external oxidizing/reducing agents. Hydrodefluorination and aminodefluorination of a range of fluoroarenes was realized with good to very good yields under mild conditions. Experimental and computational mechanistic studies show that the phosphines undergo oxidative addition of the fluoroaromatic substrate via a Meisenheimer-like transition state to form a fluorophosphorane. This undergoes a pseudotransmetalation step with a silane, via initial fluoride transfer from P to Si, to give experimentally observed phosphonium ions. Hydride transfer from a hydridosilicate counterion then leads to a hydridophosphorane, which undergoes reductive elimination of the product to reform the phosphine catalyst. This behavior is analogous to many classical transition-metal-catalyzed reactions and so is a rare example of both functional and mechanistically metallomimetic behavior in catalysis by a main-group element system. Crucially, the reagents used are cheap, readily available commercially, and easy to handle, making these reactions a realistic prospect in a wide range of academic and industrial settings.

Original languageEnglish
Pages (from-to)2005-2014
Number of pages10
JournalJournal of the American Chemical Society
Volume146
Issue number3
Early online date11 Jan 2024
DOIs
Publication statusPublished - 24 Jan 2024

Bibliographical note

Funding Information:
This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 860322. We are grateful to the CNRS (Centre National de la Recherche Scientifique) and the University of York for providing access to facilities. J.M.L. is supported by an Industry Fellowship from the Royal Society (INF\R1\221057). Part of the computational work in this project was undertaken on the Viking Cluster, which is a high-performance computer facility provided by the University of York. The authors are grateful for computational support from the University of York High Performance Computing service, Viking and the Research Computing team. The authors are grateful to Professor Robin Perutz for very helpful and insightful discussions.

Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.

Keywords

  • Anions
  • Cations
  • Group 14 compounds
  • Group 15 compounds
  • Ions
  • Catalysis

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