| Project/Area Number |
12650854
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
KATAGIRI Toshimasa Okayama University, Graduate School of Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (70202009)
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| Co-Investigator(Kenkyū-buntansha) |
UNEYAMA Kenji Okayama University, Graduate School of Science and Technology, Professor, 大学院・自然科学研究科, 教授 (00033150)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Fluoninated Organic Compounds / Intra-molecular Nuclecphilic Ssubstitution / Amlno Acid / Trifluoromenthyl Group / Optically Aclive / Electronic Reculsion / Steric Effect / 有機フッ素化合物 / ピロリジン / シクロプロパン / ジアステレオ選択性 |
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| Research Abstract |
Intramolecular S_N2 reactions of α-trifluoromethylated secondary alcohols and utilization of them to preparations of fluorinated amino acids have been studied.
2-Trifluoromethyl aziridines are synthesized from N-alkyl-3,3,3-trifluoro-2-hydroxypropylamine with triphenylphosphine-tetrachloromethane or dichlorotriphenyl-phosphorane. Similarly, 2-trifluoromethylated pyrroridines was prepared. A stereoselective intramolecular cyclization of 3-substituted-3-cyano-l-trifluoromefliylpropyl sulfonate via the cyano stabilized carbanion provides l-substituted-1-cyano-2-trifluoromefliylcyclopropanes in good yields. The stereochemistry of the product at the carbon attached to trifluoromethyl group was completely inverted its configuration from the starting alcohol, revealing the reaction underwent in S_N2 manner with Walden inversion at the reaction center. Intramolecular electrostatic repulsions between the local negative charge on a trifluoromethyl group and that on ortho positions of aryl moiety of nucleophile was found to be a controlling factor of the diastereoselectivity in the cyclopropanation. The reaction was applied for syntheses of optically active trifluoro-norcoronamic acid and its diastereomer.
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