Me3SiCl-Promoted Three-Component Coupling Reaction of a Functionalized Enamine, an Acetal, and an Alkyne: An Unprecedented Approach to the Synthesis of Tetrasubstituted Pyridines via a [3 + 2 + 1] Intermolecular Cyclization

We have identified a Me3SiCl-mediated three-component coupling reaction of a functionalized enamine, N,N-dimethylformamide diethyl acetal, and an internal alkyne having an electron-withdrawing group that produces 2,3,4,5-tetrasubstituted pyridine derivatives in good to excellent yields via a single-step reaction.