Synthesis of Benzimidazo[2,1- a ]isoquinoline and Indolo[2,1- a ]isoquinoline Derivatives via Copper-Catalyzed Silylation/Methylation of 2-Arylindoles and 2-Arylbenzimidazoles.

A one-pot method for the synthesis of silylsubstituted/methylsubstituted indolo[2,1- a ]isoquinolin-6(5 H )-ones and benzimidazo[2,1- a ]isoquinoline-6(5 H )-ones via copper(II)-initiated silylation/methylation of 2-arylindoles and 2-arylbenzimidazoles was developed. In this procedure, the C-Si bond and C-C bond were constructed by radical addition and cyclization. A series of 2-arylindole and 2-arylbenzimidazole derivatives were facilely transformed to indolo[2,1- a ]isoquinolines and benzimidazo[2,1- a ]isoquinolines in 39-83% yields.