Synthesis of multiply substituted 1,6-dihydropyridines through Cu(I)-catalyzed 6-endo cyclization.

Copper-catalyzed 6-endo cyclization of N-propargylic β-enaminocarbonyls was developed for the synthesis of oxidation-labile 1,6-dihydropyridines. This synthetic method allows flexible and regio-defined assembly of various substituents at the N1, C2, C3, C4, and C6 positions of 1,6-dihydropyridines under mild conditions.