Defluorinative Alkylboration of Alkenes Enabled by Dual Photoredox and Copper Catalysis

Abstract 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.