Copper-Catalyzed Tandem Azide–Alkyne Cycloaddition, Ullmann Type C–N Coupling, and Intramolecular Direct Arylation

Abstract

A ligand-free copper-catalyzed tandem azide–alkyne cycloaddition (CuAAC), Ullmann-type C–N coupling, and intramolecular direct arylation has been described. The designed strategy resulted in the synthesis of a novel trazole-fused azaheterocycle framework. The reaction gave good yields (59–77%) of 1,2,3-triazole-fused imidazo[1,2-a]pyridines in a single step.