Convenient Synthesis of Functionalized Tetracyclic Dihydrochromeno[2,3-b]pyrrolo[3,4-e]pyridine-triones via Four-Component Reactions

Abstract In this research, a simple and efficient strategy for the straightforward synthesis of tetracyclic dihydrochromeno[2,3-b]pyrrolo[3,4-e]pyridine-trione derivatives is presented by a sequential four-component reaction of arylamines, dimethyl acetylenedicarboxylate, alkylamines, and 3-formylchromones as readily available starting materials in MeOH at room temperature. The merit of this sequential enamine formation/1,2-nucleophilic addition/intramolecular aza-Michael addition is highlighted by its high energy conserving (short reaction times at room temperature), excellent yields, metal-free catalyst, easy purification (the products can be purified by simple filtration and washing with EtOH), and green and mild conditions in a one-pot reaction. Presumably, there are no previous reports for the synthesis of these classes of heterocyclic dihydrochromeno[2,3-b]pyrrolo[3,4-e]pyridine-trione derivatives.