title: Dimethylsilyl ketene acetal as a nucleophile in asymmetric Michael reaction: enhanced enantioselectivity in oxazaborolidinone-catalyzed reaction.
abstract: [reaction: see text] Dimethylsilanyl [Me2Si(H)] ketene S,O-acetal 6b is an effective nucleophile that retards the undesirable Si+-catalyzed racemic pathway in the oxazaborolidinone-catalyzed asymmetric Michael reaction. Through the further suppression of the Si+-catalyzed pathway by carrying out the reaction in the presence of 2,6-diisopropylphenol and t-BuOMe as additives, enantioselectivity up to 98% ee could be achieved for a variety of acyclic enones.
authors.affiliation: Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan. harada@chem.kit.ac.jp
authors.forename: Toshiro
authors.initials: T
authors.lastname: Harada
authors.forename: Shinya
authors.initials: S
authors.lastname: Adachi
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wang