Radical Desulfur-Fragmentation and Reconstruction of Enol Triflates: Facile Access to α-Trifluoromethyl Ketones.

We report an efficient oxidative radical desulfur-fragmentation and reconstruction of enol triflates for the synthesis of α-CF ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF radical from the triflyl group of enol triflate and subsequent addition of the CF radical to another enol triflate form the desired α-CF ketones. This method provides a new approach to α-CF ketones, featuring the utilization of catalytic amount of oxidants, broad substrate scope, and potential to control the regioselectivity.