title: Asymmetric Michael addition of malonates to enones catalyzed by a primary β-amino acid and its lithium salt.
abstract: Highly enantioselective Michael addition of malonates to enones was achieved using a mixed catalyst consisting of a primary β-amino acid, O-TBDPS (S)-β-homoserine, and its lithium salt. Various cyclic and acyclic enones were converted into 1,5-ketoesters in high yields (up to 92%) with high enantioselectivity (up to 97% ee) under mild reaction conditions. Details of synthesis of the catalyst, optimization of the reaction conditions for the Michael addition reaction, and a plausible reaction mechanism are described.
authors: Division of Chemical Process Engineering, Graduate School of Engineering, Hokkaido University, Kita 13-jo Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan. myoshida@eng.hokudai.ac.jp
authors: Masanori
authors: M
authors: Yoshida
authors: Mao
authors: M
authors: Narita
authors: Shoji
authors: S
authors: Hara
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis*; D002384:Catalysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D006714:Homoserine / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates / Q000737:chemistry*; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D007659:Ketones; D008314:Malonates; D017646:Organosilicon Compounds; D012492:Salts; C009660:t-butyldimethylsilyl compounds; D006714:Homoserine; D008094:Lithium