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.
Hutson
Gerri E
GE
Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA.
Dave
Apurva H
AH
Rawal
Viresh H
VH
D002255:Carbonic Acid / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
D005029:Ethylenediamines; D003035:Cobalt; D002255:Carbonic Acid; C011452:disalicylaldehyde ethylenediamine