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 FeCl(3)-catalyzed cleavage of sp(3) carbon-nitrogen bonds to generate benzyl cation intermediates. In the presence of 10 mol % of FeCl(3), a broad range of N-benzylic sulfonamides smoothly react with internal alkynes, alkynylcarbonyl compounds, alkynyl chalcogenides, or alkynyl halides to afford various functionalized indene derivatives with extremely high regioselectivity.

FeCl3‐catalyzed cleavage of the carbon—nitrogen bond in N‐benzylic sulfinamides produces benzyl cation intermediates which react with alkynes to give functionalized products with very high regioselectivity.