Stereoselective Synthesis of 2,3-Dihydropyrroles from Terminal Alkynes, Azides, and α,β-Unsaturated Aldehydes via N-Sulfonyl-1,2,3-triazoles

A stereoselective method for synthesis of trans-2,3-disubstituted 2,3-dihydropyrroles is reported. N-Sulfonyl-1,2,3-triazoles prepared from terminal alkynes generate α-imino rhodium carbene complexes, which when combined with α,β-unsaturated aldehydes produce trans-2,3-disubstituted dihydropyrroles. The method can be successfully applied to a one-pot process starting from terminal alkynes.