Metal-controlled Reversal of Enantioselectivity in Catalyzed Asymmetric Ring-opening Reactions of meso-Epoxides in Water

Reversal of enantioselectivity in Cu-chiral bipyridine catalyzed asymmetric ring-opening reactions of meso-epoxides with indole and aniline derivatives was observed compared to Sc-chiral bipyridine catalyzed reactions, where the same chiral ligand was used. It was revealed from X-ray crystal structural analysis that a square pyramidal structure for the Cu(II) complex and a pentagonal bipyramidal structure for the Sc(III) complex were formed, which could explain the reversal of the enantioselectivity.