Exploitation of Electrochemical Reaction System suitable for Oxidation of Hardly Oxidizable Organic Compounds

与传统氧化方法相比，电化学氧化具有多种优点。例如，有机化合物的氧化是在不使用任何氧化剂的情况下实现的。然而，高氧化电位有机化合物的电化学氧化一直是电化学方法的难点。本研究的目的是开发适合有效氧化这类有机化合物的溶剂体系。得到了以下结果：1)三氟乙醇电化学氧化：n -甲氧羰基-2,2,2-三氟乙胺是一种难氧化的化合物，在三氟乙醇溶剂体系中可以电化学氧化。ii)含吸电子基取代芳香族化合物的电化学氧化：含吸电子基的甲苯衍生物在三氟乙醇溶剂体系中电化学氧化得到相应苯甲醛衍生物的缩醛。iii)醚的电化学氧化：脂肪族饱和醚在三氟乙醇溶剂体系中氧化得到-三氟乙氧基化醚。iv) -丁内酯的电化学氧化：三氟乙醇溶剂体系使我们能够氧化-丁内酯，这是传统氧化方法无法氧化的。v)高效反应体系的开发：考察了上述有机化合物大规模电化学氧化的反应条件（电极材料、温度、电流密度等）。硫代苯甲醚作为介质的使用在当前效率方面取得了良好的结果。

Electrochemical oxidation has a variety of advantages in comparison with conventional oxidation methods. For example, the oxidation of organic compound is achieved without any use of oxidizing reagents. However, the oxidation of organic compounds possessing high oxidation potentials has been so far difficult by electrochemical method. The purpose of this study was to exploit solvent systems suitable for efficient oxidation of such organic compounds. The following results were obtained.i) Electorhchemical oxidation in trifluoroethanol : N-Methoxycarbonyl-2,2,2-trifluoroethylamine, hardly oxidizable compound, could be oxidized by electrochemical oxidation in trifluoroethanol solvent system.ii) Electorchemical oxidation of aromatic compounds substituted with electron-withdrawing group : Electrochemical oxidation of toluene derivatives possessing electron-withdrawing group in trifluoroethanol solvent system gave the acetals of the corresponding benzaldehyde derivatives.iii) Electorchemical oxidation of ethers : Aliphatic saturated ethers were oxidized in trifluoroethanol solvent system to give alpha-trifluoroethoxylated ethers.iv) Electrochemical oxidation of gamma-butyrolactones : Trifluoroethanol solvent system allowed us to oxidize gamma-butyrolactones, which has not been oxidized by conventional oxidation methods.v) Exploitation of highly efficient reaction systems : Reaction conditions for large scale electrochemical oxidation of organic compounds as described above were scrutinized (electrode materials, temperature, current density, and so on). The use of thioanisole as a mediator gave a good result in respect of current efficiencies.