A General Proline-Catalyzed Synthesis of 4,5-Disubstituted N-Sulfonyl-1,2,3-Triazoles from 1,3-Dicarbonyl Compounds and Sulfonyl Azide.

An efficient proline-catalyzed synthesis of 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles has been accomplished from 1,3-dicarbonyl compounds and sulfonyl azides. The developed reaction is suitable for various symmetrical and unsymmetrical 1,3-dicarbonyl compounds, tolerates various functional groups and affords 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles in good yield with excellent regioselectivity. Rhodium-catalyzed denitrogenative functionalization of 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles further demonstrates their utility in organic synthesis.