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1998 Fiscal Year Final Research Report Summary

Catalytic Asymmetric Formation and Reactions of Lithium Enolates and Elucidation of their Mechanisms

Research Project

Project/Area Number 09470482
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Chemical pharmacy
Research InstitutionResearch and Education Center for Materials Science, Nara Institute of Science and Technology (1998)
The University of Tokyo (1997)

Principal Investigator

KOGA Kenji  Professor, Graduate School of Pharmaceutical Sciences, University of Tokyo (1997) ; Professor, Research and Education Center for Materials Science, Nara Institute of Science and Technology (1998), 物質科学教育研究センター, 教授 (10012600)

Co-Investigator(Kenkyū-buntansha) AOKI Kazumasa  Assistant, Graduate School of Pharmaceutical Sciences, University of Tokyo (1997, 大学院・薬学系研究科(平成9年度), 助手 (60282612)
Project Period (FY) 1997 – 1998
KeywordsLithium Enolate / Catalytic Asymmetric Deprotonation / Catalytic Asymmetric Alkylation / Catalytic Asymmetric Protonation / Chiral Bidentate Lithium Amide / Chiral Tetradentate Amine / Lithium-Hydrogen Interchange / Lignad Exchange
Research Abstract

Formation and reactions of lithium enolates constitute the most fundamental processes frequently employed in synthetic organic chemistry. We have previously reported novel enantioselective asymmetric deprotonation, alkylation, and protonation reactions. The purpose of the present research is to make these enantioselective asymmetric reactions catalytically asymmetric reactions as to the chiral amines used as chiral auxiliaries.
To make these reactions catalytically asymmetric, it is necessary to find out conditions in which the reactions influenced by chiral auxiliaries proceed reasonably faster than those not influenced by chiral auxiliaries. Based on the studies on the mechanisms of these reactions, we examined various possibilities that satisfy such conditions.
In enantioselective asymmetric deprotonation reactions of prochiral carbonyl compounds. we have found that the rates of deprotonation by bidentate chiral lithium amides proceed faster than those by tridentate lithium amides. We … More have also found that in situ lithium-hydrogen interchange reactions between chiral bidentate amine and achiral tridentate lithium amides occur rapidly favoring the formation of either sides, depending on the structures of these two species. Thus, using a combination of less than a stoichiometric amount of chiral bidentate amines and more than a stoichiometric amount of achiral tridentate lithium amides having appropriate structures, catalytic asymmetric deprotonation reactions as to the chiral bidentate amines were realized for the first time.
In the enantioselective asymmetric alkylation reactions of prochiral lithium enolates, we have found that the rates of alkylation in the presence of bidentate amines are not enhanced, while those in the presence of tetradentate amines are reasonably enhanced. Thus, expecting fast ligand exchange reactions to the lithium between tetradentate chiral amines and bidentate achiral amines, catalytic asymmetric alkylation reactions were realized for the first time using a combination of less than a stoichiometric amount of chiral tetradentate amines and more than a stoichiometric amount of achiral bidentate amines. The same strategy was successfully applied to catalytic asymmetric protonation reactions. Less

  • Research Products

    (22 results)

All Other

All Publications (22 results)

  • [Publications] Shirai, R. ; Koga,K.et al.: "Enantioselective Deprotonation of Prochiral 4-Substituted Cyclohexanones by Chiral Chelated Lithium Amides" Tetrahedron. 53. 5963-5972 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Sato, D, ; Koga, K.et.al.: "Solution Structures of a Chiral Bidentate Lithium Amidein Relation to the Solvent-Dependent Enantioselectivities" Tetrahedron. 53. 7191-7200 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Rivierre, P. ; Koga, K.et.al.: "An Approach to Catalytic Enantioselective Protonation of Prochiral Lithium Enolates" Tetrahedron Letters. 38. 7589-7592 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yamashita, T. ; Koga, K.et.al.: "An Approach to Catalytic Enantioselective Deprotonation" Tetrahedron. 53. 16987-16998 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Murakata, K. ; Koga, K.et.al.: "Enantioselective Alkylation of the Lithium Enolates of Six-Membered Cyclic Ketones Using Tetradentate Chiral Amine" Tetrahedron. 54. 2449-2458 (1998)

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      「研究成果報告書概要(和文)」より
  • [Publications] Yamashita, Y.Koga, K.et.al.: "Construction of Chiral Quaternary Carbon Centers by Asym-metric Alkylation of Achiral Lithium Enolates" Tetrahedron Letters. 40(in press). (1999)

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      「研究成果報告書概要(和文)」より
  • [Publications] Toriyama, M. ; Sugasawa, K. ; Shindo, M. ; Tokutake, N. ; Koga, K.: "Stereochemistry of Enantioselective Deprotonation of 4-Substituted Cyclohexanones by Chiral Bidentate Lithium Amides." Tetrahedron Lett.38. 567 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Aoki, K. ; Koga, K.: "Enantioselective Deprotonation of 4-tert-Butylcyclohexanone by Fluorine-Containing Chiral Lithium Amides Derived from alpha-Phenethylamine" Tetrahedron Lett.38. 2505 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Kumamoto, T. ; Koga, K.: "Enantioselective Horner-Wadsworth-Emmons Reaction Using Chiral 2-Amino-alkoxides" Chem.Pharm.Bull.45. 753 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Shirai, R. ; Sato, D. ; Aoki, K. ; Tanaka, M. ; Kawasaki, H. ; Koga, K.: "Stereoselective Reactions.XXV.Enantioselective Deprotonation of Prochiral 4-Substituted Cyclohexanones by Chiral Chelated Lithium Amides" Tetrahedron. 53. 5963 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yasuda, K. ; Shindo, M. ; Koga, K.: "Construction of Contiguous Chiral Tertiary Carbon Centers by Enantioselective Michael Reaction of Ketone Lithium Enolates Using a Chiral Amine Ligand" Tetrahedron Lett.38. 3551 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Sato, D. ; Kawasaki, H. ; Shimada, I. ; Arata, Y. ; Okamura, K. ; Date, T. ; Koga, K.: "Stereoselective Reactions.XXVI.Solution Structures of a Chiral Bidentate Lithium Amides in Relation to the Solvent-Dependent Enantioselectivities in Deprotonation Reaction" Tetrahedron. 53. 7191 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Sato, D. ; Kawasaki, H. ; Koga, K.: "Enantioselective Reactions.XXXVII.Solution Structures of a Chiral Tridentate Lithium Amide in Relation to Enantioselective Deprotonation of 4-tert-Butylcyclohexanone" Chem.Pharm.Bull.45. 1399 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Aoki, K. ; Tomioka, K. ; Noguchi, H. ; Koga, K.: "Stereoselective Reactions.XXVIII.Effects of the Alkyl Group at the Amide Nitrogen of Chiral Bidentate Lithium Amides on Enantioselective Deprotonation Reaction" Tetrahedron. 53. 13641 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Rivierre, P. ; Koga, K.: "An Approach to Catalytic Enantioselective Protonation of Prochiral Lithium Enolates" Tetrahedron. 38. 7589 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yamashita, T. ; Sato, D. ; Kiyoto, T. ; Kumar, A. ; Koga, K.: "Stereoselective Reactions.XXIX.Lithium-Hydrogen Interchange between Achiral Tridentate Lithium Amides and Chiral Bidentate Amine. An Approach to Catalytic Enantioselective Deprotonation" Tetrahedron. 53. 16987 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Chatani, H. ; Nakajima, M. ; Kawasaki, H. ; Koga, K.: "Chiral Bidentate Lithium Amides Having a Chiral Amide Nitrogen for Enantioselective Deprotpnation of 4-tert-Butylcyclohexanone" Heterocycles. 46. 53 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Matsuo, J. ; Koga, K.: "Enantioselective alpha-Alkylation of Phenylacetic Acid Using a Chiral Bidentate Lithium Amide as a Chiral Auxiliary" Chem.Pharm.Bull.45. 2122 (1997)

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      「研究成果報告書概要(欧文)」より
  • [Publications] Tomioka, K. ; Okuda, M. ; Nishimura, K. ; Manabe, S. ; Kanai, M. ; Nagaoka, Y. ; Koga, K.: "Structural Requirement of a Chiral Ligand for the Catalytic Asymmetric Addition to Thiophenol to alpha, beta-Unsaturated Esters" Tetrahedron Lett.39. 2141 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Murakata, M. ; Yasukata, T. ; Aoki, T. ; Nakajima, M. ; Koga, K.: "Stereoselective Reactions.XXX.Enantioselective Alkylation of the Lithium Enolates of Six-Membered Cyclic Ketones Using Tetradentate Chiral Amine in the Presence of Lithium Bromide" Tetrahedron. 54. 2449 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Shindo, M. ; Koga, K. ; Tomioka, K.Design: "Synthesis, and Application of a C_2-Symmetric Chiral Ligand for Enantioselective Conjugate Addition of Organolithium to alpha, beta-Unsaturated Aldimine" J.Org.Chem.63. 9351 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yamashita, Y. ; Odashima, K. ; Koga, K.: "Construction of Chiral Quaternary Carbon Centers by Asymmetric Alkylation of Achiral Lithium Enolates Mediated by Chiral Tetradentate Ligands : Stochiometric and Catalytic Approaches" Tetrahedron Lett.(in press.).

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      「研究成果報告書概要(欧文)」より

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Published: 1999-12-08  

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