Novel Organic Synthesis Catalyzed by Hydrophobic Vitamin B_<12> Derivatives under Electrochemical Conditions

电化学条件下疏水性维生素B_<12>衍生物催化新型有机合成

• 批准号: 63850174
• 负责人: MURAKAMI Yukito
• 金额: $ 6.53万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63850174/
• 关键词: Hydrophobic Vitamin B_<12>; Polymer-coated Electrode; Catalytic Reaction; Isomerization; Rearrangement; Modified Electrode; Electrolysis; Electrochemistry; タ-ンオ-バ-; アルキル化反応; 軸性キラリティ; アニオン中間体; 電子吸引性置換基

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

维生素B_<12>依赖酶催化各种异构化反应，其中伴随碳骨架重排的酶因其催化性质而受到特别关注。为了模拟维生素B_<12>在相关酶的疏水活性位点所发挥的各种催化功能，我们一直在研究疏水维生素B_<12>衍生物。在本研究中，我们首次证明了疏水维生素B_<12>在电化学条件下催化的碳骨架重排反应。然后制备了疏水性维生素B_<12>修饰的聚合物包被碳电极，并将其用于碳骨架重排反应。在疏水维生素B_<12>的催化下，烷基卤化物发生了各种吸电子基团的控制电位电解反应，并通过阴离子中间体的形成进行了电化学碳骨架重排。在碳原子上有两个吸电子基团的底物，一个羧酸酯和一个羧酸酯、乙酰基和氰基的组合，很容易产生相应的重排产物，这些重排产物是由取代基的单个迁移产生的。吸电子基团的迁移倾向从大到小依次为：COR > COR > CO_2R > CN。疏水维生素B_<12>，其氰基部分位于核钴的轴向位置，进一步增强了电化学碳骨架重排。以疏水维生素B_<12>和Araldite CT-200为可聚合单体在玻碳电极上制备了聚合物包覆电极，并将其应用于具有吸电子基团的烷基卤化物的碳骨架重排反应。以疏水维生素B_<12>为原料制备的碳骨架重排产物为主要产物，产率较高。少

项目成果

Yukito Murakami: Chemistry Letters. 469-472 (1988)

村上幸人：化学快报。

Yukito Murakami: "Redox Behavior of Simple Vitamin B_<12> Model Complexes and Electrochemical Catalysis of Carbon-Skeleton Rearrangements" Bulletin of the Chemical Society of Japan. 62. 2045-2049 (1989)

Yukito Murakami：“简单维生素B_<12>模型复合物的氧化还原行为和碳骨架重排的电化学催化”日本化学会会刊。

Yukito Murakami: "Preparation and Reactivity of Hydrophobic Vitamin B_<12> Derivatives Having an Intramolecular Axial Base" Nippon Kagaku Kaishi, 445-451, 1988.

Yukito Murakami：“具有分子内轴向碱基的疏水性维生素B_<12>衍生物的制备和反应性”Nippon Kagaku Kaishi，445-451，1988。

Yukito Murakami: "Redox Behavior of Simple Vitamin B_<12> Mosel Complexes and Electrochemical Catalysis of Carbon-Skeleton Rearrangements" Bulletin of Chemical Society of Japan. 62. 2045-2049 (1989)

Yukito Murakami：“简单维生素B_<12>摩泽尔络合物的氧化还原行为和碳骨架重排的电化学催化”日本化学会会刊。

Yukito Murakami: "Redox Behavior of Simple Vitamin B_<12> Model Complexes with Cobalt-Carbon Bonds and Catalytic Carbon-Skeleton Rearrangements" Chemistry Letters, 835-838, 1988.

Yukito Murakami：“具有钴碳键和催化碳骨架重排的简单维生素 B_<12> 模型复合物的氧化还原行为”化学快报，835-838，1988。