Copper-catalyzed tandem azide-alkyne cycloaddition, Ullmann type C-N coupling, and intramolecular direct arylation
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.