Synthesis of α-Difluoromethyl Aryl Ketones through a Photoredox Difluoromethylation of Enol Silanes.

We report here an efficient and highly straightforward access to α-difluoromethylated ketones through a visible light-mediated difluoromethylation of readily available enol silanes. The method, which takes advantage of the polyvalence of Hu's reagent, N-tosyl-S-difluoromethyl-S-phenylsulfoximine, used here as a CHF2 radical precursor under catalytic photoredox conditions, is practical, scalable, and provides the corresponding α-CHF2 ketones in good to excellent yields.