| Project/Area Number |
07405059
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
有機工業化学
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| Research Institution | Osaka Institute of Technology |
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Principal Investigator |
NISHINAGA Akira Faculty of Engineering, Department of Applied Chemistry, Osaka Institute of Technology, Professor, 工学部, 教授 (80025882)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Oxygen / Oxidation / Oxygenation / Cobalt / Enzyme model / Super acid-base catalysis / Superoxo complex / ESR / 一酸化窒素 / ニトロソ化合物 / 反応場制御 / フェノール |
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| Research Abstract |
1.Field Control of Catalytic Activity of Model Oxygenase Complex. In biomimetic oxygenations of phenols, the reaction between a phenoxy radical intermediate and a superoxometal complex is promoted by model oxygenase complexes in the presence of a coordinative organic base. The model oxygenase complxes also catalyze the dehydrogenation of 2-aminophenols by oxygen leading to highly selective formation of 2-aminophenoxazin-3-ones, where a binary complex intermediate comprised of 2-iminoquinone and catalyst plays an important role as judged by ESR studies. It has also been found that the active species of the model oxygenase complexes catalyze carbon-carbon bond formation by Michael and aldol reactions, and highly regioselective solvoltic cleavage of epoxides controlled by the structure of the catalyst as well. These catalytic reactions are caused by field controlled super acid-base catalysis of the active species. These results provide interesting information in the biomimetic chemistry.
2. Chemical Reactivity of Superoxocobalt (III) Complexes. It is found that coordinately unsaturated superoxocobalt (III) complexes catalyze the oxygenation of stirenes in the presence of sodium borohydride leading to the selective formation of 1-phenylethanols, whereas a coordinately saturated superoxocobalt (III) complex oxidizes nitrosobenzenes to nitrobenzenes selectively. ESR studies show that the oxidation of nitroso compounds involves radical addition of the superoxo species to the nitroso group.
The chemistry of superoxocobalt (III) complexes with nitrogen monoxide and of mixed metal mu-peroxo complexes is currently investigated.
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