Defluoroalkylation of sp3 C−F Bonds of Industrially Relevant Hydrofluoroolefins |
| |
Authors: | Dr Nicholas A Phillips Gregory J Coates Dr Andrew J P White Dr Mark R Crimmin |
| |
Institution: | Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, 80 Wood Lane, White City, Shepherds Bush, London, W12 0BZ UK |
| |
Abstract: | A 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. |
| |
Keywords: | C−F functionalisation defluoroalkylation fluorine HFOs trifluoromethyl |
|
|