Phillips, Nicholas ANicholas APhillipsCoates, Gregory JGregory JCoatesWhite, Andrew JPAndrew JPWhiteCrimmin, Mark RMark RCrimmin2020-04-082021-03-252020-04-24Chemistry: A European Journal, 2020, 26 (24), pp.5365-53680947-6539http://hdl.handle.net/10044/1/77880A simple, one‐pot procedure is reported for the selective defluoroalkylation of trifluoromethyl alkene derivatives with aldehydes and ketones. The reaction sequence allows construction of a new C−C bond in a highly selective manner from a single sp3 C−F bond of a CF3 group in the presence of sp2 C−F bonds. The scope incorporates industrially relevant fluorocarbons including HFO‐1234yf and HFO‐1234ze. No catalyst, additives or transition metals are required, rather the methodology relies on a recently developed boron reagent. Remarkably, the boron site of this reagent plays a dual role in the reaction sequence, being nucleophilic at boron in the C−F cleavage step (SN2’) but electrophilic at boron en route to the carbon–carbon bond‐forming step (SE2’). The duplicitous behaviour is underpinned by a hydrogen atom migration from boron to the carbon atom of a carbene ligand.© 2020 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim. This is the accepted version of the following article: [Phillips, N.A., Coates, G.J., White, A.J.P. and Crimmin, M.R. (2020), Defluoroalkylation of sp3 C−F Bonds of Industrially Relevant Hydrofluoroolefins. Chem. Eur. J.. doi:10.1002/chem.202000636], which has been published in final form at https://doi.org/10.1002/chem.202000636Science & TechnologyPhysical SciencesChemistry, MultidisciplinaryChemistryC-F functionalisationdefluoroalkylationfluorineHFOstrifluoromethylTRIFLUOROMETHYL ALKENESDEFLUOROSILYLATIONBORYLJournal Articlehttps://www.dx.doi.org/10.1002/chem.202000636https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/chem.2020006366773671521-3765