Rh(III)-Catalyzed One-Pot Synthesis of Benzimidazoquinazolines via C–H Amidation–Cyclization of <i>N</i>‑LG-2-phenylbenzoimidazoles

An efficient protocol to synthesize substituted benzo­[4,5]­imidazo­[1,2-c]­quinazolines starting from N-LG-2-phenylbenzoimidazole and dioxazolones catalyzed by Rh­(III) or Ir­(III) has been developed. Various substituted benzo­[4,5]­imidazo­[1,2-c]­quinazolines could be easily provided in up to 99% yield. A large range of substrates and functional groups are compatible for this transformation. This method features low catalyst loading, acid-free conditions, and low solvent consumption