Catalytic Cycle for Palladium-Catalyzed Decarbonylative Trifluoromethylation using Trifluoroacetic Esters as the CF₃ Source

This paper demonstrates a catalytic cycle for Pd-catalyzed decarbonylative trifluoromethylation using trifluoroacetic esters as CF 3 sources. The proposed cycle consists of four elementary steps: (1) oxidative addition of a trifluoroacetic ester to Pd 0, (2) CO deinsertion from the resulting trifluoroacyl Pd II complex, (3) transmetalation of a zinc aryl to Pd II, and (4) aryl–CF 3 bond-forming reductive elimination. The use of RuPhos as the supporting ligand enables each of these steps to proceed under mild conditions (<100 °C). These studies set the stage for the development of catalytic arene trifluoromethylation and perfluoroalkylation reactions using inexpensive trifluoroacetic acid derived CF 3 sources.