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.