| Project/Area Number |
06453189
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Chemical pharmacy
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
FUJI Kaoru Kyoto University, Institute for Chemical Research Professor, 化学研究所, 教授 (20027056)
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| Co-Investigator(Kenkyū-buntansha) |
KAWABATA Takeo Kyoto University, Institute for Chemical Research Instructor, 化学研究所, 助手 (50214680)
TANAKA Kiyoshi Kyoto University, Institute for Chemical Research Associate Professor, 化学研究所, 助教授 (50093266)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1995: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1994: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | Axial Chirality / Asymmetric Protonation / Asymmetric Olefination / 1,1'-Binaphthalene-2,2'-diol / 1,1'-Binaphthalene-8,8'-diol / Wittig Reaction / 軸不斉化合物 / 不斉合成 / Horner-Wadsworth-Emmons反応 / エノレート / α-ジケトン / σ-対称 / プロキラル |
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| Research Abstract |
This research project has dealt with asymmetric synthesis using axially chiral compounds which possess 1,1'-binaphthalene skeleton. Especially, asymmetric Wittig reaction and asymmetric protonation were examined. Since Wittig reaction creates sp^2 carbon, its application to asymmetric synthesis had rather been limited. We demonstrated asymmetrization of sigma-symmetrical meso-compounds through discrimination of enantiotopic carbonyls of alpha-diketones. Using chiral phosphonates having 1,1'-binaphthalene-2,2'-diol moiety as a chiral auxiliary, highly enantioselective Wittig-type reactions were achieved with rigid cyclic alpha-diketones. Intramolecular Asymmetric Witting-type reactions were also performed to afford polycyclic ketones in moderate to high enantioselectivity.
Since protonation is one of the most simple operations out of chemical transformations, asymmetric protonation of enolates should have wide variety of applications to production of optically active carbonyl compounds. We have investigated asymmetric protonation using chiral proton sources having 1,1'-binaphthalene-8,8'-diol moiety. Enantioselectivity of the protonation depended strongly on the countercation of the enolates. While the lithium enolate of an alpha-tetralone derivative gave the products of only 9% ee, the corresponding magnesium enolare afforded the product of 94% ee.
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