Electropositive Sulfur Activation for the Regioselective Amino Functionalization of Alkynyl Sulfonium Salts

We report an electropositive sulfur activation strategy for regioselective alkyne amination, enabling the tunable amino functionalization of alkynyl sulfonium salts with triazoles under ambient conditions. The operationally simple protocol exhibits a broad substrate scope and excellent functional-group tolerance, delivering vinyl triazoles in moderate to excellent yields. Both the control experiments and the isolation of key intermediates support a stepwise reaction pathway for this chemical process.