Electrophotocatalytic perfluoroalkylation by LMCT excitation of Ag(II) perfluoroalkyl carboxylates.

Molecular Ag(II) complexes are super-oxidizing photoredox catalysts capable of generating radicals from redox reticent substrates. Herein, we exploit the electrophilicity of Ag(II) centers in [Ag(bpy) 2 (TFA)][OTf] and Ag(bpy)(TFA) 2 complexes to activate trifluoroacetate (TFA) by visible-light-induced homolysis. The resulting trifluoromethyl radicals may react with a variety of arenes to forge C(sp 2 )-CF 3 bonds. This methodology is general and extends to other perfluoroalkyl carboxylates of higher chain length (R F CO 2 - ; R F = CF 2 CF 3 or CF 2 CF 2 CF 3 ). The photoredox reaction may be rendered electrophotocatalytic by regenerating the Ag(II) complexes electrochemically during irradiation. Electrophotocatalytic perfluoroalkylation of arenes at turnover numbers exceeding 20 is accomplished by photoexciting the Ag(II)-TFA ligand-to-metal charge transfer (LMCT) state followed by electrochemical re-oxidation of the Ag(I) photoproduct back to the Ag(II) photoreactant.