Highly Efficient Asymmetric [3+2] Cycloaddition Promoted by Chiral Aziridine-Functionalized Organophosphorus Compounds

Abstract

The asymmetric [3+2] cycloaddition of azomethine ylides generated from the corresponding imino ester-to-trans-β-nitrostyrene catalysis by chiral aziridine-containing phosphines and phosphine oxides is described. Of the sixteen stereoisomers that could be formed as a result of the title reaction, three were formed, two of which were obtained in an enantiomerically enriched or pure form, and one in a racemic form. One of the products underwent epimerization under basic reaction conditions.

Keywords

• asymmetric cycloaddition
• aziridines
• chiral ligands/catalysts
• enantioselective synthesis