Six-Component Telescope Assembly of sp3-Rich Hexahydro-pyrrolo[3,4-c]pyridine-1,6-diones via Sequential Enaminone Formation, Aza-Annulation, Hydrogenation, and Ugi Cyclization

We report a six-component, four-step telescope sequence that enables rapid access to structurally complex, sp3-enriched hexahydro-1H-pyrrolo[3,4-c]pyridine-1,6(2H)-dione scaffold. The streamlined protocol integrates enaminone formation, intramolecular aza-annulation, heterogeneous alkene hydrogenation, and a three-component Ugi cyclization within a single operational sequence requiring only one purification step. This approach unites multicomponent and tandem reaction principles to deliver diastereomerically defined products featuring four contiguous stereocenters. The method demonstrates high atom economy and modular diversification through systematic variation of isocyanide and amine inputs.