| Project/Area Number |
16550104
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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 | Toyama National College of Technology |
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Principal Investigator |
KAWAFUCHI Hiroyuki Toyama National College of Technology, Department of Chemical and Biochemical Engineerings, Professor, 物質工学科, 教授 (20195134)
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| Co-Investigator(Kenkyū-buntansha) |
INOKUCHI Tsutomu Okayama University, Faculty of Engineering, Department of Bioscience and Biotechnology, Associate Professor, 工学部・生物機能工学科, 助教授 (50168473)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Cobalt Complex / Electrochemical Reaction / Zinc Electrode / 1,4-Hydroquinone / O-Alkyloxime / β-Aminoacetal / Radical Cyclization / Three Component Combination Reaction / コバロキシム / マンニッヒ塩基 / シクロペンタン-1,3-ジオン / シクロヘキサン-1,4-ジオン / ジアリール誘導体 / 環拡大反応 |
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| Research Abstract |
We developed a tin-free method for carbon radical generation by using cobaloxime, which was used as a mimic of metalloenzyme vitamine B_<12>. Regeneration of low valency cobalt catalyst was carried out by electroreduction with a sacrifical Zn anode in an undivided cell system. Development of a catalytic radical generation method is very meaningful in the synthesis of commonly useful compounds.
1.We investigated the 1,2-acyl rearrangement of 2-(halomethyl)cyclopentane-1,3-diones, giving the corresponding cyclohexane-l,4- diones by the electrochemical radical generation method. This reaction was utilized for the synthesis of functionalized biaryls. The electroreduction of monoacetals of 2-(halomethyl)cyclopentane-1,3-diones in the presence of cobaloxime as a catalyst afforded the cyclohexane-1,4-dione monoacetals in good yields. The Bu_3SnH-reduction of 2-aryl-2-(halomethyl)cyclopentane- 1,3-diones under refluxing in benzene resulted in the rearrangement, affording the corresponding cyclohexane-1,4-diones, and 1,4- hydroquinones proceeded in moderate yields when heating was prolonged.
2.We present here the radical cyclization reaction of O-alkyloximes by using cobalt complex-sacrificial electrode system, giving functionalized β-aminoacetals. The radicals generated from primary, secondary, and tertialy alkyl bromides added to the carbon- nitrogen double bonds without any difficulty and difference in their reactivity. This reaction seems to be slightly influenced by steric factor in the cyclization process.
3.We investigated the three component combination reaction of bromoacetal with benzaldehyde, giving the corresponding cyclization product by the electrochemical radical generation method. The best result was obtained by using [Co^<III>(N_4)Cl_2]ClO_4 as a cobalt complex.
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