Selective C–F Bond Allylation of Trifluoromethylalkenes

Abstract Selective C−F bond functionalization of CF 3 group represents an appealing strategy for the incorporation of pharmaceutically privileged difluoromethylene moiety. Despite the recent significant advancement attained in the functionalization of Ar‐CF 3 molecules, prescriptions amenable for alkenyl‐CF 3 congeners remain sufficiently inadequate. Herein, we report a strategically novel protocol for the C−F bond elaboration of trifluoromethylalkene derivatives. By using readily available allyl metallics as nucleophilic coupling partner, the present reaction enables an expedient construction of structurally diversified CF 2 ‐bridged 1,5‐dienes. Furthermore, the exquisite selectivity observed in this transformation is revealed to be based on the underlying mechanism that consists of a cascade of nucleophilic S N 2′ defluorinative allylation and electronically promoted Cope rearrangement.