A new model for the stereoselectivities of dihydroxylations of alkenes by chiral diamine complexes of osmium tetroxide

Abstract

A symmetrical five-membered transition structure model for the dihydroxylations of alkenes by chiral diamine complexes of osmium tetraoxide has been developed based on X-ray crystal structures of OsO₄‒amine complexes and osmate esters and ab initio transition structures of analogous reactions. The MM2 calculations based upon this model reproduce the stereoselectivities observed with a variety of chiral diamine ligands. Some predictions are also made using this force field.