Catalyst- and additive-free selective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones leading to sulfonylated γ-butyrolactams

Abstract A convenient and regioselective sulfonylation/cyclization of 1,6-enynes with arylazo sulfones has been developed to access a series of sulfonylated γ-butyrolactams. The present reaction could be efficiently conducted under catalyst- and additive-free conditions, in which C–S and C-C bonds were selectively constructed in one-pot procedure.