1,3-Dipolar Cycloaddition of Imidate Ylides on Imino-Alcohols: Synthesis of New Imidazolones Using Solvent Free Conditions.

Article abstract of DOI:10.1016/0040-4020(95)00321-X

Imidates derived from α-amino esters as potential azomethine ylides, undergo 1,3-dipolar cycloaddition with imino-alcohols, in tautomeric equilibrium with 1,3-oxazolidines, without solvent at 70 deg C or under microwave irradiation.This reaction leads to a wide range of novel polyfunctionalized 4-yliden-2-imidazolin-5-ones in good yields with short reaction times.The reactivity of these imidates derived from α-amino esters with imino-alcohols is rationalized from the energy of the Frontier Molecular Orbitals (FMO) determined by semi-empirical PM3 calculations : the reaction is controlled by the interaction HOMO_(1,3-dipole) - LUMO_{(dipolarophile)} and the second order perturbation energy calculations are in agreement with the experimental reaction orientation.