Dysprosium(III) trifluoromethanesulfonate is a water-tolerant Lewis acid used in the Aldol reaction of silyl enol ethers with aldehydes. This is an effective catalyst for electrophilic substitution reactions of indoles with imines. Also used as catalyst for Aza-Piancatelli rearrangement, Friedel-Crafts alkylation, ring-opening polymerization reactions, microwave-assisted Kabachnik-Fields condensation, cycloaddition reactions (Lewis-acid catalyst), fries rearrangement and enantioselective glyoxalate-ene reactions.