Three-component reaction of N'-(2-alkynylbenzylidene)hydrazide, alkyne, with sulfonyl azide via a multicatalytic process: a novel and concise approach to 2-amino-H-pyrazolo[5,1-a]isoquinolines.

A novel and efficient route for the synthesis of 2-amino-H-pyrazolo[5,1-a]isoquinolines via a three-component reaction of N'-(2-alkynylbenzylidene)hydrazide, alkyne, and sulfonyl azide is described. This transformation, co-catalyzed by silver triflate and copper(I) bromide under mild conditions, proceeds efficiently to generate the 2-amino-H-pyrazolo[5,1-a]isoquinolines in good to excellent yields.