Controlling Factors in Chiral Bisoxazoline-Catalyzed Asymmetric Lithium Ester Enolate-Imine Condensation Producing a β-Lactam
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概要
- 論文の詳細を見る
A catalytic amount of external chiral bisoxazoline ligand 3a bearing an isopropyl group as a stereocontrolling group catalyzed a reaction of a lithium ester enolate 4b, generated from 3-pentyl 2-methylpropionate, with benzaldehyde anisidine-imine 5 to afford corresponding β-lactam 6 in higher 70% ee than that obtained by the reaction using a stoichiometric amount of the ligand. A bulkier ligand 3d bearing a phenyl group gave 81% and 6% ees in stoichiometric and catalytic reactions, respectively. Examination of the varying factors suggested the involvement of mixed aggregates as a reactive species. A working model is presented for prediction of the sense of asymmetric induction.
- 公益社団法人日本薬学会の論文
- 2000-10-01
著者
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TOMIOKA Kiyoshi
Graduate School of Pharmaceutical Sciences, Kyoto University
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Tomioka Kiyoshi
Graduate School Of Pharmaceutical Sciences Kyoto Univ.
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Kambara Takeshi
Graduate School Of Pharmaceutical Sciences Kyoto University
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Kambara Takeshi
Graduate School of Information Systems, University of Electro-Communications:Department of Applied Physics and Chemistry, University of Electro-Communications
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