One-Pot Cascade Reactions Leading to Pyrido[2′,1′:2,3]imidazo[4,5‑c][1,2,3]triazolo[1,5‑a]quinolines under Bimetallic Relay Catalysis with Air as the Oxidant

In this paper, we report an efficient one-pot synthesis of 1,2,3-triazole/quinoline-fused imidazo­[1,2-a]­pyridines starting from 2-(2-bromophenyl)­imidazo­[1,2-a]­pyridines, alkynes, and sodium azide. This novel method involves a one-pot bimetallic relay-catalyzed cascade process combining azide–alkyne cycloaddition, C–N coupling between 1,2,3-triazole and aryl bromide, and intramolecular cross dehydrogenative C–C coupling between 1,2,3-triazole and imidazo­[1,2-a]­pyridine. Notable features of this protocol include simple starting materials, sustainable oxidants, reduced synthetic steps, and high efficiency.