Pd(II)-catalyzed ortho-trifluoromethylation of arenes using TFA as a promoter.

A Pd(II)-catalyzed C-H activation/trifluoromethylation of arenes with an electrophilic trifluoromethylation reagent using diverse heterocycle directing groups is reported. The presence of trifluoroacetic acid is crucial for this catalytic reaction.