Asymmetric Dipolar Cycloaddition of Nitrile Oxides to the α,β-Unsaturated Esters Bearing an Imidazolidine Chiral Controller at the β-Position

Article abstract of DOI:10.1246/bcsj.64.3274

Some α,β-unsaturated esters bearing an imidazolidine chiral controller at the β-position were employed in the asymmetric cycloaddition to nitrile oxides.Regio- and diastereoselectivities were both poor when the chiral controller was a perhydropyrrolo<1,2-c>imidazol-3-yl auxiliary, while the reaction of the esters bearing a C2-symmetric imidazolidine chiral controller was exclusively regioselective or diastereoselective depending upon the nature of N-substituent.The transition state was briefly discussed.