Regio-selective synthesis of diversely substituted benzo[a]carbazoles through Rh( iii )-catalyzed annulation of 2-arylindoles with α-diazo carbonyl compounds

A novel synthetic approach toward benzo[ a ]carbazoles and 6-aminobenzo[ a ]carbazoles containing an unprotected NH unit through Rh( iii )-catalyzed cascade reactions of 2-arylindoles or 2-arylindole-3-carbonitriles with α-diazo carbonyl compounds is presented.