Umpolung using Electroorganic Reaction - Carbon-Carbon Bond Forming Reaction by the use of Sulfonates as a Nucleophile.

使用有机电反应进行 Umpolung - 使用磺酸盐作为亲核试剂进行碳-碳键形成反应。

• 批准号: 15550082
• 负责人: FUKUHARA Tsuyoshi
• 金额: $ 2.43万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15550082/
• 关键词: Electroorganic chemistry; Electroorganic synthesis; Alkyl sulfonates; Carbon-Carbon bond formation; Umpolung; Reactive metal anode; Electrochemical reduction; Mediator; アルコールの合成

Electrochemical reduction (ER) of 3-phenylpropyl tosylate gave 3-phenyl-1-propanol predominantly. On the other hand, a similar ER of 3-phenylpropyl mesylate in the presence of ketones, such as cyclohexanone, resulted in C-C bond forming reaction between mesylate and ketone to obtain the corresponding 1-(3-phenylpropyl)cycloalkanol in up to 30% yields. However, the yields of C-C bond forming reaction products could not be improved even though the reaction was carried out under various reaction conditions.We next tried ER of alkyl mesylates to the corresponding alkanes. A constant current electrolysis of 1-dodecyl mesylate with a platinum cathode and a magnesium anode in DMF in the presence of polycyclic aromatic compounds such as naphthalene, biphenyl and phenanthrene exclusively gave desired n-dodecane in moderate yields. After optimization of reaction conditions, it was found that n-dodecane could be obtained in 74% yield when ER of 1-dodecyl mesylate was carried out in the presence of biphenyl (4 equiv.) and t-BuOH (10 equiv.). This reaction system was applicable to various alkyl mesylates having epoxide, olefin, ester, acetal, and cyano groups to obtain the corresponding alkanes in good yields without change of these functional groups.In connection with the present research, ER of aliphatic ketones in the presence of carbon dioxide was also carried out, and it was found that an efficient fixation of CO_2 at a-position of carbonyl group in saturated aliphatic ketones could be achieved by a constant current electrolysis of the ketones in a CH_3CN or DMF solution with a platinum cathode and a magnesium anode under an atmospheric pressure of CO_2 to obtain the corresponding β-keto carboxylic acids in moderate to good yields.

对甲苯磺酸3-苯丙酯的电化学还原(ER)主要生成3-苯基-1-丙醇。另一方面，类似的3-苯丙基甲酸苯丙酯在酮(如环己酮)存在下的ER，导致甲磺酸与酮之间的C-C键形成反应，以高达30%的产率得到相应的1-(3-苯丙基)环烷醇。然而，即使在不同的反应条件下进行反应，也不能提高C-C成键反应产物的产率。接下来，我们尝试了甲酸烷基酯到相应烷烃的ER。1-十二烷基甲酸酯在DMF中以铂为阴极，镁为阳极，在多环芳香族化合物如萘、联苯和菲的存在下进行恒流电解，以适中的产率得到所需的正十二烷。通过对反应条件的优化，发现在联苯(4当量)存在下对甲酸十二酯进行电流变反应，可得到产率为74%的正十二烷。和t-BuOH(10当量)。该反应体系适用于含有环氧化物、烯烃、酯、缩醛和氰基的各种烷基甲磺酸酯，在不改变这些官能团的情况下，以较高的产率获得相应的烷烃。结合本研究，还进行了脂肪酮在二氧化碳存在下的ER反应，发现在CH3CN或DMF溶液中，通过在CH3CN或DMF溶液中，以铂为阴极，镁为阳极，在常压CO2的条件下，通过恒流电解脂肪酮，以中等到较高的产率获得相应的β-酮基羧酸。