Copper-Catalyzed Multicomponent Domino Reaction of 2-Bromobenzaldehydes, Aryl Methyl Ketones, and Sodium Azide: Access to 1H-[1,2,3]Triazolo[4,5-c]quinoline Derivatives

A practical copper-catalyzed multicomponent reaction has been developed for the synthesis of 1H-[1,2,3]triazolo[4,5-c]quinoline derivatives from commercially available 2-bromobenzaldehydes, aryl methyl ketones, and sodium azide. This protocol integrated consecutive base-promoted condensation, [3 + 2] cycloaddition, copper-catalyzed SNAr, and denitrogenation cyclization sequences. Preliminary mechanistic studies revealed that CuBr2 acted as a multifunctional catalyst to streamline this domino process. The mild catalytic system enabled effective construction of one C–C and four C–N bonds in one operation.