The first catalytic asymmetric addition of dialkylzincs to alpha-ketoesters.
[formula: see text] The first catalytic, enantioselective addition of organoznic reagents to alpha-ketoesters is described. Modular bifunctional salen catalysts that contain Lewis acid and Lewis base activating groups accelerate the carbonyl addition to a much greater extent than the competing carbonyl reduction. alpha-Hydroxyesters containing new quaternary stereogenic centers are obtained in high yield and moderate enantiomeric excess. Enrichment to 98% ee can be effected by recrystallization of the corresponding alpha-hydroxy acid.
DiMauro
Erin F
EF
Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Kozlowski
Marisa C
MC
D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
D004952:Esters; D007659:Ketones; D009942:Organometallic Compounds; D015032:Zinc