Enamine chemistry. Part 27. The effect of additional α- and β-heteroatoms on the p π -conjugation and reactivity of enamines. Sub or super-enamines

Enamines derived from isoxazolidine and 1,3-dioxa-5-azacyclohexane have been prepared. The effect of the addition a α- or β-heteroatoms is to decrease the pπ-conjugation between the nitrogen lone pair of electrons and the π-electrons of the double bond, as reflected in the spectral properties of the enamines and their reactivity with electrophiles. The reasons for this are discussed.