MICROWAVE-IRRADIATED SYNTHESIS OF 1,2-DIHYDROPYRIDlNES FROM W-FUNCTIONALIZED ENAMINONES AND ENALS THROUGH DOMINO CONDENSATION AND 6Π-AZAELECTROCYCL1ZATION

摘要

N-Amino-substituted 1,2-dihydropyridine motifs are constructed using cyclohexane-l,3-diones via the Knoevenagel condensation with enals followed by 6π-electrocyclization using ethylenediammonium diacetate as a catalyst under MW irradiation. A survey of substituents on the N atom of the enaminones indicated that the phenylamino and benzoylamino groups are favorable for the reaction, while phenyl, benzyl, and no-substituent are not. The substituent at C2 of enals is crucial for smooth formation of the corresponding adducts and slightly higher yields are obtained with enals bearing an electron-withdrawing aromatic at C3.