Organocatalyzed Modular Synthesis of Polycyclic Dihydropyridines and Pyridines through Sulfamate Linchpin.

The cascade annulation between alkylidene malononitriles and cyclic sulfamidate imines has been controlled by leveraging the sulfamate functionality under organocatalysis, which allows selective access to polycyclic and densely functionalized dihydropyridines and pyridines in high yields. The protocol is scalable and shows broad substrate scope. The products were also engaged in the preparation of tetracyclic pyridopyrimidines, showcasing the synthetic versatility.