One-pot CuI/ l -proline-catalysed multicomponent synthesis of pyrido[2′,1′:2,3]imidazo[4,5- c ]quinoline derivatives from 2-(2-bromophenyl)imidazo[1,2- a ]pyridines, NH ₃ and DMSO under air

Pyrido[2′,1′:2,3]imidazo[4,5- c ]quinolines (PIQs) were prepared from 2-(2-bromophenyl)imidazo[1,2- a ]pyridines, NH 3 and DMSO via a tandem process including CuI/ l -proline-catalysed C–N coupling and aerobic oxidative cyclization steps.