Tandem C-2 Functionalization-Intramolecular Azide-Alkyne 1,3-Dipolar Cycloaddition Reaction: A Convenient Route to Highly Diversified 9H-Benzo[b]pyrrolo[1,2-g][1,2,3]triazolo[1,5-d[1,4]diazepines

An efficient diversity-oriented synthetic approach to annulated 9H-benzo[b]pyrrolo[1,2-g][1,2,3]triazolo[1,5-d][1,4]diazepines has been developed using a R Sc(OTf)(3)-catalyzed two-component tandem C-2 functionalization intramolecular azide-alkyne 1,3-dipolar cycloaddition reaction. The reaction shows high substrate tolerance and provides a library of fused heterocycles that may. lead to novel biologically active compounds or drug lead molecules.