Radical Desulfur-Fragmentation and Reconstruction of Enol Triflates: Facile Access to [alpha]-Trifluoromethyl Ketones

We report an efficient oxidative radical desulfur-fragmentation and reconstruction of enol triflates for the synthesis of [alpha]-CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enol triflate and subsequent addition of the CF3 radical to another enol triflate form the desired [alpha]-CF3 ketones. This method provides a new approach to [alpha]-CF3 ketones, featuring the utilization of catalytic amount of oxidants, broad substrate scope, and potential to control the regioselectivity.