| Project/Area Number |
11650891
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
KUWANO Ryoichi Kyoto University, Graduate School of Engineering, Assistant Professor, 工学研究科, 助手 (20273477)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Catalytic Asymmetric Synthesis / Chiral Phosphine / Asymmetric Hydrogenation / Indoline / Heteroaromatics / Indole / Rhodium / 光学活性ピラジン / 複素芳香環 / 水素化 / 光学活性化合物 |
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| Research Abstract |
1. Catalytic Hydrogenation of Heteroaromatic Compounds using Transition Metal Complex
We found that rhodium complex generated from Rh (acac)(cod) and triphenylphosphine exhibited high catalytic activity for hydrogenation of indoles. The rhodium catalyst was also effective in hydrogenation of other 5-membered heteroaromatic compounds.
2. Catalytic Asymmetric Hydrogenation of 2-Substituted Indoles
The hydrogenation of N-acetyl-2-butylindole proceeded in the presence of cataionic (S, S)-(R,R)-PhTRAP-rhodium complex and cesium carbonate, giving (R)-N-acetyl-2-butylindoline with 94% ee in 92% isolated yield. This reaction is the first example of highly enantioselective hydrogenation of 5-membered heteroaromatic compounds. The chiral catalyst showed high enantioselectivity for the hydrogenation of other 2-substituted indoles (up to 95% ee).
3. Catalytic Asymmetric Hydrogenation of 3-Substituted Indoles
The chiral PhTRAP-rhodium catalyst exhibited good enantioselectivity (86% ee) for the hydrogenation of N-acetyl-3-methylindole, but the reaction was accompanied by serious alcoholysis of N-acetyl group. p-Toluenesulfonyl group is the protective group on nitrogen of choice in asymmetric hydrogenation of 3-substituted indoles. The hydrogenation of 3-methyl-N-p-toluenesulfonylindole gave the corresponding indoline with 98% ee in 93% isolated yield.
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