Heptadecafluorooctanesulfonic acid (C8F17SO3H) catalyzed intramolecular hydroamination of olefinic sulfonamides in fluorous biphase system (FBS)

A practical, efficient, and environmentally benign intramolecular hydroamination of olefinic sulfonamides was carried out in fluorous biphase system (FBS) using commercially available heptadecafluorooctanesulfonic acid (C8F17SO3H) as a catalyst and perfluorodecaline (C10F18, cis- and trans- mixture) as a fluorous solvent to produce the corresponding cyclic products in good yields. The Brّnsted acid of C8F17SO3H is easily recovered and recycled at least five times.