Copper-Mediated Radical 1,2-Bis(trifluoromethylation) of Alkenes with Sodium Trifluoromethanesulfinate

An efficient chemoselective 1,2-bis(trifluoromethylation) of alkenes with CF3SO2Na promoted by t-BuOOH/CuCl was developed. This protocol provided the first convenient preparation of 1,2-bis(trifluoromethylated) compounds by the vicinal difunctionalization of alkenes. The chemoselectivity of this reaction was accomplished by increasing the concentration of the CF3 radical.