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

对甲苯磺酸3-苯丙酯经电化学还原主要生成3-苯基-1-丙醇。另一方面，甲磺酸3-苯丙酯在酮如环己酮存在下的类似ER导致甲磺酸酯和酮之间的C-C键形成反应，以高达30%的产率获得相应的1-（3-苯丙基）环烷醇。然而，即使在各种反应条件下进行反应，C-C键形成反应产物的产率也不能提高。在DMF中，以铂为阴极，镁为阳极，在萘、联苯和菲等多环芳烃存在下，对甲磺酸1-十二烷基酯进行恒电流电解，以中等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，甲磺酸十二烷基酯进行ER反应，可得到正十二烷，产率为74%。和t-BuOH（10当量）。该反应体系适用于含环氧基、烯烃基、酯基、缩醛基和氰基的各种甲磺酸烷基酯，在不改变这些官能团的情况下，以良好的产率得到相应的烷烃。发现在CH_3中恒电流电解饱和脂肪酮可有效地将CO_2固定在羰基的α位上。3CN或DMF溶液中，以铂为阴极，镁为阳极，在常压CO_2下，以中等至良好的产率得到相应的β-酮基羧酸。

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.