Palladium-catalyzed C-H trifluoromethylselenolation of arenes with [Me 4 N][SeCF 3 ] and an oxidant.

Trifluoromethylselenolation of arenes with [Me 4 N][SeCF 3 ] in the presence of an oxidant through Pd-catalyzed C(sp 2 )-H activation under the assistance of a directing group is established for the first time. The reaction tolerates different directing groups and a variety of functional groups, enabling selective installation of a SeCF 3 moiety onto the ortho positions of arenes. Mechanistic studies revealed that the CF 3 SeSeCF 3 intermediate in situ generated from oxidation of [Me 4 N][SeCF 3 ] might be the real SeCF 3 reagent in the reaction.