Defluorinative Alkylboration of Alkenes Enabled by Dual Photoredox and Copper Catalysis

A regioselectivity reversed three‐component defluorinative alkylboration of alkenes with trifluoromethyls and bis(pinacolato)diboron via dual photoredox/copper catalysis is reported. The mild conditions are compatible with a wide array of nonactivated trifluoromethyl aromatics bearing electron‐donating or electron‐neutral substituents, trifluoroacetamides, and various nonactivated terminal and internal alkenes, enabling straightforward access to synthetically valuable γ‐gem‐difluoroalkyl boronates with high efficiency. Furthermore, this protocol is applicable to alkene‐tethered trifluoromethyl aromatics to furnish gem‐difluoromethylene‐containing cyclic compounds. Synthetic applications and preliminary mechanistic studies are also presented. Reported here is a radical‐based three‐component defluorinative alkylboration of alkenes with trifluoromethyls and bis(pinacolato)diboron via dual photoredox/copper catalysis. This protocol offers efficient access to synthetically valuable γ‐gem‐difluoroalkyl boronates with high efficiency and reversed regioselectivity.