INTRAMOLECULAR CYCLOADDITION OF AZOMETHINE YLIDES ACTIVATED BY AROMATIC RINGS: SCOPE AND LIMITATIONS

Abstract

Simple aromatic substituents in the substrate molecule, including pyrimidine, pyridine, and benzene rings, directly facilitated the intramolecular cycloaddition of azomethine ylide to alkene. All of these aromatic substituents aided the formation of azomethine ylides, which then underwent highly diastereospecific sequential cycloaddition. It was shown that both the presence of an electron-deficient aromatic ring and a substituent at ortho position of the aromatic ring relative to the aminomethyl group enhanced the reactivity of azomethine ylides towards cycloaddition.