An unprecedented protocol has been developed for the regioselective synthesis of structurally diverse indene derivatives from readily accessible N-benzylic sulfonamides and disubstituted alkynes through FeCl3-catalyzed cleavage of sp3 carbon− nitrogen bonds to generate benzyl cation intermediates. In the presence of 10 mol% of FeCl3, a broad range of N-benzylic sulfonamides smoothly react with internal alkynes, alkynylcarbonyl compounds ...
