Palladium-Catalyzed Heck-Type Difluoroalkylation of Alkenes with Functionalized Difluoromethyl Bromides

An efficient method for the synthesis of difluoroalkylated alkenes through palladium-catalyzed Heck-type reaction with functionalized difluoromethyl bromides has been developed. The advantages of this protocol are its synthetic simplicity, excellent functional group compatibility, and efficient late-stage difluoroalkylation of biologically relevant molecules, thus paving a new way for application in drug discovery and development. Mechanistic studies revealed that the free difluoroalkyl radicals, initiated by a [Pd(0)L-n] via a single-electron-transfer (SET) pathway, were involved in the Heck-type catalytic cycle.