Cascade [3 + 2] Annulation of 1,3-Dicarbonyl Compounds and Ethyl Secondary Amines for Pyrrole Synthesis via Poly C(sp)-H Bond Functionalization.

The synthesis of polyfunctionalized pyrroles via the cascade reactions of 1,3-dicarbonyl compounds and two molecules of ethyl secondary amines has been realized via simple iodine catalysis in the presence of Dess-Martin periodinane (DMP). The formation of the target pyrrole products involves the formation of one new C-C and two new C-N bonds via the major functionalization of six C(sp)-H bonds, presenting a highly novel and efficient synthetic protocol toward pyrrole scaffolds.