Hydrophobic Vitamin B<sub>12</sub>. V. Electrochemical Carbon-Skeleton Rearrangement as Catalyzed by Hydrophobic Vitamin B<sub>12</sub>: Reaction Mechanisms and Migratory Aptitude of Functional Groups
acid in the dark. The electrochemical carbon-skeletonrearrangement was postulated to proceed via formation of anionic intermediates. The electrolyses of 1-bromo-2-cyano-2-ethoxycarbonylpropane, 2-acetyl-1-bromo-2-ethoxycarbonylpropane, and 1-bromo-2-[(ethylthio)carbonyl]propane with [Cob(II)7C1ester]ClO4 also afforded the corresponding carbon-skeletonrearrangement products. The results indicated that
在电化学条件下研究了由高氯酸七甲基钴酸盐 [Cob(II)7Cl酯]ClO4 催化的碳骨架重排。2,2-双(乙氧羰基)-1-溴丙烷被认为是甲基丙二酰辅酶A变位酶的模型底物,由[Cob(II)7C1酯]ClO4在N,N-二甲基甲酰胺中催化的电位控制得到重排产物 1,2-双(乙氧基羰基)丙烷,作为主要产物,在 -1.5V vs. SCE 条件下,在乙酸存在下,并且比 -1.8V vs. SCE 的阴极电位更高,没有乙酸黑暗的。电化学碳骨架重排被假定通过阴离子中间体的形成进行。1-溴-2-氰基-2-乙氧基羰基丙烷、2-乙酰基-1-溴-2-乙氧基羰基丙烷的电解,和 1-溴-2-[(乙硫基)羰基]丙烷与 [Cob(II)7Cl酯]ClO4 也提供相应的碳骨架重排产物。结果表明,具有两个吸电子...
Electrochemical Carbon-Skeleton Rearrangements as Catalyzed by Cyano-Coordinated Hydrophobic Vitamin B<sub>12</sub>
Electrochemical carbon-skeletonrearrangements catalyzed by heptamethyl cobyrinate perchlorate proceeded more efficiently upon coordination of the cyanide ion to the central cobalt atom, and such enhanced catalysis was originated from facilitated formation of an anionic intermediate.
Hydrophobic vitamin B<sub>12</sub>. Part 6. Carbon-skeleton rearrangement via formation of host–guest complexes derived from an ‘octopus’ azaparacyclophane and hydrophobic vitamin B<sub>12</sub>derivatives: a novel holoenzyme model system
species via formation of a ternary complex composed of the octopus cyclophane, the hydrophobic vitaminB12derivative, and an alkyl halide. Carbon-skeletonrearrangements reactions of alkylligands bound to the hydrophobic vitaminB12 were found to be markedly favoured in the hydrophobic cavity provided by the octopus cyclophane, relative to the reactions in methanol and benzene, under anaerobic photolysis
The cobalt complex of 2,10-diethyl-3,9-dipropyl-1,4,8,11-tetraazaundeca-1,3,8,10-tetraene-1,11-diol catalyzed electrolyses of alkyl halides with electron-withdrawing groups at the β-position to afford rearrangement products via oxidation of the corresponding dialkylated complexes as intermediates.
A glassy carbon electrode was coated with a polymer species derived from a hydrophobic vitaminB12 and Araldite CT-200,and the immobilised cobalt complex catalysed the electrochemical carbon-skeletonrearrangements of alkyl halides having electron-withdrawing groups.