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2002 Fiscal Year Final Research Report Summary

Elucidation of the Enantioselection Mechanism of Transition Metal-Catalyzed Asymmetric Reactions

Research Project

Project/Area Number 13440186
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Organic chemistry
Research InstitutionCHIBA UNIVERSITY

Principal Investigator

IMAMOTO Tsuneo  Chiba University, Faculty of Science, Professor, 理学部, 教授 (10134347)

Co-Investigator(Kenkyū-buntansha) DANJO Hiroshi  Chiba University, Faculty of Science, Research Associate, 理学部, 助手 (70332567)
Project Period (FY) 2001 – 2002
KeywordsAsymmetric Synthesis / Asymmetric Hydrogenation / Rhodium Complexes / Optically Active Phosphine / Catalyst / Reaction Mechanism
Research Abstract

This study is directed toward the elucidation of the enantioselection mechanism of rhodium-catalyzed asymmetric hydrogenation that is one of the representative asymmetric catalyses. P-Chirogenic, electron-rich diphosphines such as BisP^* and MiniPHOS were used in this study because of their simple molecular structure and very high enantioinduction ability in rhodium-catalyzed asymmetric hydrogenations of α- or β-and dehydroamino acid derivatives, enamides, and enol esters. One of the most important findings is the detection and characterization of the rhodium dihydride complexes bearing diphosphine ligands. The dihydride complexes reacted readily with the alkene substrates even at -100 - -90 ℃ to give the corresponding monohydride intermediates, and subsequent reductive elimination occurred at about -50 ℃. These results are interpreted by considering a dihydride mechanism. It is concluded that the enantioselection is determined at the stage of the migratory insertion of the Rh-H to the C-C double bond. The main factors to control the enantioselection are 1. Trans effect of by the coordinated phosphorus atom, 2. The orbital interaction between of the Rh-H and the C-C double bond, 3. Formation of the chelate cycle, 4. The steric interaction between the bulky group at the phosphorus and the chelate cycle, 5. Electronic effect of the substituent at the olefic group. It is also concluded that the enantioselection of these Rh-catalyzed asymmetric hydrogenations is governed by multi stereo regulation factors. A new quadrant rule to correlate between the stereochemistry of the hydrogenation products and the structure of the catalyst structures has been proposed. A new, highly efficient chiral diphosphine ligand has been designed and synthesized based on these research results.

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] I.D.Gridnev, M.Yasutake, N.Higashi, T.Imamoto: "Asymmetric Hydrogenation of Enamides with Rh-BisP^* and Rh-MiniPHOS Catalysts. Scope, Limitations, and Mechanism"J.Am.Chem.Soc.. 123. 5268-5276 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.Yasutake, I.D.Gridnev, N.Higashi, T.Imamoto: "Highly Enantioselective Hydrogenation of (E)-β-(Acylamino)acrylates Catalyzed by Rh(I)-Complexes of Electron-Rich P-Chirogenic"Org.Lett.. 3. 1701-1704 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] I.D.Gridnev, N.Higashi, T.Imamoto: "Formation of Stable Rhodium(III) Dihydride Complex and Its Reactions with Prochiral Substrates of Asymmetric Hydrogenation"Organometallics. 20. 4542-4553 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] H.Danjo, W.Sasaki, T.Miyazaki, T.Imamoto: "P-Chirogenic Phosphonium Salts : Preparation and Use in Rh-Catalyzed Asymmetric Hydrogenation of Enamides"Tetrahedron Lett.. 44. 3467-3469 (2003)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.V.L.Crepy, T.Imamoto: "Recent developments in Catalytic Asymmetric Hydrogenation Employing P-Chirogenic Diphosphines"Adv.Synth.Catal.. 345. 79-101 (2003)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K.V.L.Crepy, T.Imamoto: "New P-Chiral Phosphine Ligands and Their Use in Catalytic Asymmetric Reactions"Topics in Current Chemistry. 3(in press). (2003)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] I. D. Gridnev, M. Yasutake, N. Higashi. And T. Imamoto: "Asymmetric Hydrogenation of Enami with Rh-BisP^* and Rh-MiniPHOS Catalysts. Scope, Limitations, and Mechanism"J. Am. Chem. Soc.. 123 No.22. 5268-5276 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M. Yasutake, I. D. Gridnev, N. Higashi, and T. Imamoto: "Highly Enantioselective Hydrogenation of (E)-b-(Acylamino)acrylates Catalyzed by Rh(I)- Complexes of Electron-Rich P-Chirogenic Diphosphines"Org. Lett.. 3 No.11. 1701-1704 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] I. D. Gridnev, N. Higashi, and T. Imamoto: "Formation of Stable Rhodium(III) Dihydride Complex and Its Reactions with Prochiral Substrates of Asymmetric Hydrogenation"Organometallics. 20 No.22. 4542-4553 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H. Danjo, W. Sasaki, T. Miyazaki, and T. Imamoto: "P-Chirogenic Phosphonium Salts : Preparation and Use in Rh-Catalyzed Asymmetric Hydrogenation of Enamides"Tetrahedron Lett. 44. 3467-3469 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K. V. L. Crepy and T. Imamoto: "Recent developments in Catalytic Asymmetric Hydrogenation Employing P-Chirogenic Diphosphines"Adv. Synth. Catal. 345, No.1. 79-101 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K. V. L. Crepy, and T. Imamoto: "New P-Chiral Phosphine Ligands and Their Use in Catalytic Asymmetric Reactions"Topics in Current Chemistry: New Aspects in Phosphorus Chemistry. III, in press.

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2004-04-14  

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