1989 Fiscal Year Final Research Report Summary
Novel Organic Synthesis Catalyzed by Hydrophobic Vitamin B_<12> Derivatives under Electrochemical Conditions
| Project/Area Number |
63850174
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
有機工業化学
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| Research Institution | Kyushu University |
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Principal Investigator |
MURAKAMI Yukito Kyushu University, Department of Organic Synthesis, Professor, 工学部, 教授 (30037717)
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| Co-Investigator(Kenkyū-buntansha) |
IMAI Hirosuke Nippon Petrochemicals Company, Limited Director of Research, 研究部, 部長
OHNO Teruhisa Kyushu University, Department of Organic Synthesis, Research Associate, 工学部, 助手 (10203887)
HISAEDA Yoshio Kyushu University, Department of Organic Synthesis, Associate Professor, 工学部, 助教授 (70150498)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Hydrophobic Vitamin B_<12> / Polymer-coated Electrode / Catalytic Reaction / Isomerization / Rearrangement / Modified Electrode / Electrolysis / Electrochemistry |
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| Research Abstract |
Vitamin B_<12>-dependent enzymes catalyze various isomerization reactions, and the ones accompanied with carbon-skeleton rearrangements are of particular interest in view of their catalytic nature. We have been dealing with hydrophobic vitamin B_<12> derivatives in order to simulate various catalytic functions of vitamin B_<12> as exerted in the hydrophobic active sites of enzymes concerned. In this study, we demonstrate for the first time the carbon-skeleton rearrangement reactions catalyzed by a hydrophobic vitamin B_<12> under electrochemical conditions. Then, we prepared a polymer-coated carbon electrode, as modified with a hydrophobic vitamin B_<12>, and used it for the carbon-skeleton rearrangement reactions.
The controlled-potential electrolyses of alkyl halides with various electron-withdrawing groups as catalyzed by a hydrophobic vitamin B_<12> were carried out, and the electrochemical carbon-skeleton rearrangements proceeded via formation of anionic intermediates. Substrates w
… More
ith two electron- withdrawing groups placed on the beta-carbob atom, combinations of one carboxylic ester and one of carboxylic ester, acetyl, and cyano moieties, readily gave the corresponding rearrangement products which were derived from individual migration of the substituent groups. The apparent migratory aptitude of electron-withdrawing groups was found to decrease in the order: COSR > COR > CO_2R > CN. A hydrophobic vitamin B_<12> with the cyano moiety at an axial site of the nuclear cobalt further enhanced the electrochemical carbon-skeleton rearrangement.
The polymer-coated electrode was prepared with a hydrophobic vitamin B_<12> and Araldite CT-200 as a polymerizable monomer on the glassy carbon electrode, and applied to the carbon-skeleton rearrangement reactions of alkyl halide, having electron-withdrawing groups under electrochemical conditions. The carbon-skeleton rearrangement products were obtained as major ones, and the yields based on the hydrophobic vitamin B_<12> were quite large. Less
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