Photoredox Generation of Carbon‐Centered Radicals Enables the Construction of 1,1‐Difluoroalkene Carbonyl Mimics

Described is a facile, scalable route to access functional‐group‐rich gem‐difluoroalkenes. Using visible‐light‐activated catalysts in conjunction with an arsenal of carbon‐radical precursors, an array of trifluoromethyl‐substituted alkenes undergoes radical defluorinative alkylation. Nonstabilized primary, secondary, and tertiary radicals can be used to install functional groups in a convergent manner, which would otherwise be challenging by two‐electron pathways. The process readily extends to other perfluoroalkyl‐substituted alkenes. In addition, we report the development of an organotrifluoroborate reagent to expedite the synthesis of the requisite trifluoromethyl‐substituted alkene starting materials. CF3 today, CF2 tomorrow: Described is a facile, scalable route to access functional‐group‐rich gem‐difluoroalkenes. Trifluoromethyl‐substituted alkenes readily undergo radical defluorinative alkylation using visible‐light‐activated catalysts and an arsenal of C‐radical precursors. Nonstabilized primary, secondary, and tertiary radicals can be used to install various functional groups. PC=photocatalyst.