Metal-Controlled Switching of Enantioselectivity in the Mukaiyama-Michael Reaction of α,β-Unsaturated 2-Acyl Imidazoles Catalyzed by Chiral Metal-Pybox Complexes.

Abstract

Metal-directed switching of enantioselectivity in the Mukaiyama-Michael reaction of silyl enol ethers to α,β-unsaturated 2-acyl imidazoles using the same chiral indapybox ligand has been reported. The utility of this approach has been portrayed in the synthesis of both enantiomers of optically active δ-keto acid and ester as well as 3,4-dihydropyran-2-one. Moreover, enantioswitching in the construction of the tertiary stereocenter adjacent to a gem-dimethyl group has been achieved.