Synthesis of substituted benzo[ij] imidazo[2,1,5-de]quinolizine by rhodium(III)-catalyzed multiple C-H activation and annulations

The cascade oxidative annulation reactions of aryl imidazoles with two molecules of alkynes via multiple C-H activation proceed efficiently in the presence of [Cp*RhCl2](2) and Cu(OAc)(2)center dot H2O to give substituted benzo[ij] imidazo[2,1,5-de]quinolizine-based polyheteroaromatic compounds. This method is compatible with various functional groups, which are very useful for further synthetic transformations.