3-((Trifluoromethyl)thio)indoles can be synthesized by a palladium(II)-catalyzed reaction of 2-alkynylaniline with trifluoromethanesulfanylamide in the presence of bismuth(III) chloride. The presence of bismuth(III) chloride is crucial for the success of this transformation, which activates the trifluoromethanesulfanylamide during the reaction.