Copper-Catalyzed Aerobic Cascade Oxidative Coupling/Cyclization for the Construction of 1,4-Dihydropyridine Derivatives.

ABSTRACT

An efficient copper-catalyzed cascade cyclization reaction for the preparation of polysubstituted 1,4-dihydropyridines between N-arylglycine esters and 1,3-dicarbonyl compounds using molecular oxygen as the terminal oxidant has been described. Various N-arylglycine esters 1 and 1,3-dicarbonyl compounds 2 were able to undergo the cascade reaction smoothly to afford the desired products 3 in satisfactory yields. The cascade reaction has the advantages of good functional group tolerance and mild reaction conditions. A possible mechanism has also been proposed on the basis of control experiments.