Allylic C–H Difluoroalkylation of Unactivated Alkenes with Trifluoromethylarenes

We disclose a redox-neutral, visible-light-induced palladium-catalyzed allylic C–H difluoroalkylation of unactivated alkenes using trifluoromethylarenes as readily available electrophilic fluoroalkylating agents. The transformation proceeds via photoinduced C–F bond cleavage to generate difluorobenzyl radicals, which undergo an allylic Mizoroki–Heck-type cascade with regioselective β-hydride elimination. The gem-difluoromethylene unit plays a crucial role in directing regiochemistry, potentially by stabilizing key Pd(II) intermediates. This protocol operates under mild conditions, exhibits a broad substrate scope, and enables late-stage functionalization, providing a practical platform for the modular incorporation of bioactive difluoroalkyl groups into olefinic frameworks.