Hafnium trifluoromethanesulfonate is a recyclable catalyst for the mononitration of o-nitrotoluene. It serves as a catalyst for homogeneous methoxycarbonylation and hydrocarboxylation reactions of phenylacetylene. It is also used as a reactant for direct Friedel-Crafts reactions of chromene hemiacetals, aminomethylation reactions under Lewis acidic conditions and prins-type cyclization reactions. It is also involved in the direct polycondensation of lactic acid. Further, it is used in cationic benzylation reactions, chemoselective thioacetalization and transthioacetalization of carbonyl compounds.
