One‐Pot Three‐Component Synthesis of 3‐nitro‐2‐arylimidazo[1,2‐a]pyridine Derivatives Using Air as an Oxidant

A novel one-pot three-component synthesis of 3-nitro-2-arylimidazo[1,2-a]pyridines has been easily achieved with 2-aminopyridines, aromatic aldehydes, and MeNO2, and is catalyzed by CuBr under air. The procedure, using air as an oxidative agent, is simple, low cost, and sustainable. Various functional groups are tolerated in this reaction system, and it proceeds well with moderate to good yields.