title: Highly enantioselective carbonyl-ene reactions catalyzed by a hindered silyl-salen-cobalt complex.
abstract: 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.
authors.affiliation: Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA.
authors.forename: Gerri E
authors.initials: GE
authors.lastname: Hutson
authors.forename: Apurva H
authors.initials: AH
authors.lastname: Dave
authors.forename: Viresh H
authors.initials: VH
authors.lastname: Rawal
mesh_terms: D002255:Carbonic Acid / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D005029:Ethylenediamines; D003035:Cobalt; D002255:Carbonic Acid; C011452:disalicylaldehyde ethylenediamine