Optically active β-ketoiminato cationic cobalt(III) complexes: Efficient catalysts for enantioselective carbonyl-ene reaction of glyoxal derivatives

(formula presented) Optically active β-ketoiminato cationic cobalt(III) complexes were synthesized as effective Lewis acid catalysts for the enantioselective carbonyl-ene reaction. In the presence of a catalytic amount of cobalt(III) hexafluoroantimonate derived from the optically active 1,2-diphenyl-1,2-ethanediamine, the carbonyl-ene reaction with a variety of alkenes and glyoxal derivatives smoothly proceeded to afford the corresponding homoallylic alcohols in good-to-high yields with high enantioselectivities.