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.