Catalytic Defluoroalkylation of Trifluoromethylaromatics with Unactivated Alkenes

摘要

We describe a new catalytic approach to selective functionalization of the strong C–F bonds in trifluoromethylaromatic (Ar–CF_(3)) systems. In this approach, single electron reduction of Ar–CF_(3) substrates (using a photoredox catalyst) results in difluorobenzylic radical formation through a C–F cleavage mechanism. These radicals undergo efficient intermolecular coupling with simple alkenes in a defluoroalkylation process where radical termination is accomplished by a polarity reversal catalyst. This mild catalytic protocol engages a wide range of substrates to give medicinally relevant fluorinated substructures with complete regiocontrol.