Highly Enantioselective Carbonyl-ene Reactions Catalyzed by a Hindered Silyl−Salen−Cobalt Complex

We report here the enantioselective carbonyl-ene reactions of various 1,1-disubstituted and trisubstituted alkenes with ethyl glyoxylate. The
reactions are catalyzed by a new Co−salen complex, in which bulky triisobutylsilyl (TIBS) substituents occupy the positions ortho to the
phenolic oxygens. This complex catalyzes the reactions under nearly ideal conditionsat room temperature and using catalyst loadings as
low as 0.1 mol %and provides the chiral, homoallylic alcohol products in excellent yields, enantioselectivities, and diastereoselectivities.