Copper-catalyzed cascade synthesis of alkyl 6-aminobenzimidazo[2,1-a]isoquinoline-5-carboxylates.

A convenient and efficient copper-catalyzed cascade method has been developed for synthesis of benzimidazoisoquinoline derivatives via reactions of readily available substituted 2-(2-halophenyl)benzoimidazoles with alkyl cyanoacetates under mild condition, and the corresponding alkyl 6-aminobenzimidazo[2,1-a]isoquinoline-5-carboxylates were obtained in good to excellent yields. The novel method provides diverse and useful poly N-heterocyclic compounds for combinatorial chemistry and medicinal chemistry.