Light-Induced PdH-Catalyzed Cross-Dimerization of gem-Difluoroalkenes with Alkenes to Access CF2H Motifs.

The CF2H group constitutes a valuable structural motif in medicinal chemistry. Herein, we report an efficient light-induced palladium-catalyzed cross-dimerization of electron-deficient gem-difluoroalkenes with styrene derivatives, enabling hydroalkenylation and hydroalkylation reactions to access diverse α-difluoromethyl products. The photoenhanced hydricity of PdH species facilitates efficient insertion into gem-difluoroalkenes for the generation of α-difluoromethyl palladium species. This palladium intermediate subsequently undergoes alkyl Heck reaction with readily available alkenes without defluorination, affording C(sp3)-C(sp2) coupling products with monosubstituted alkenes, or C(sp3)-C(sp3) coupling products with 1,1-disubstituted alkenes. This protocol features mild conditions and broad functional group tolerance.