Electrochemical Fixation of Carbon Dioxide by the Use of Fluidized Electrochemical Cell-Synthesis of Useful Organic Carboxylic Acids

本研究项目的目的是开发一种利用流态化电化学池将二氧化碳电化学固定到有机底物上来制备合成有用的羧酸的有效方法。1.利用反应金属阳极--在大气二氧化碳存在下，烯丙基卤化物、丙烯基卤化物、乙烯基卤化物、三氟乙烯和1，4-二溴-2-溴甲基-2-丁烯的电化学羧化反应合成不饱和羧酸。分别给出了α，β-不饱和酸，β-酮基羧酸，2.高效合成抗炎药前体--芳基取代乙烯基溴的电化学羧化高效合成α，β-不饱和酸成功地合成了布洛芬、萘普生、氟比洛芬、环洛芬、酮洛芬等抗炎药前体。3.流态化电化学池--流态化电化学池用于电化学羧化反应。考察了不同的反应条件如二氧化碳流量、温度、通电和电流密度对肉桂基溴的电化学羧化反应的影响。各种有机卤化物在最佳条件下进行电化学羧化反应，得到相应的羧酸，包括布洛芬及其前体，产率较高。使用流态化电化学池的优点是，与通常的单室电池相比，可以在更高的产率和选择性以及更高的电流密度下进行电化学羧化反应。

The purpose of this research project is to develop an efficient preparation method of synthetically useful carboxylic acids by electrochemical fixation of carbon dioxide to organic substrates using fluidized electrochemical cell.1.Synthesis of Unsaturated Carboxylic Acids by Electrochemical Carboxylation Using a Reactive-metal Anode-Electrochemical carboxylation of allylic halides, propargylic halides, vinyl halides, vinyl triflates, and 1,4-dibromo-2-bromomethyl-2-butene in the presence of atmospheric carbon dioxide using a reactive-metal anode gave, respectively, alpha, beta-unsaturated acids, beta-keto carboxylic acids, and 3-methylene-4-pentenoic acid in high yields and in high regioselective manners.2.Efficient Synthesis of the Precursor of Anti-inflammatory Agents-Efficient synthesis of alpha, beta-unsaturated acids by electrochemical carboxylation of aryl-substituted vinyl bromides was successfully applied to a synthesis of the precursor of anti-inflammatory agents such as ibuprofen, naproxen, flurbiprofen, cicloprofen, and ketoprofen.3.Electrochemical Carboxylation Using Fluidized Electrochemical Cell-Fluidized electrochemical cell was newly made by us and used in the electrochemical carboxylation. Various reaction conditions such as flow rate of CO_2, temperature, electricity passed, and current density were examined in the electrochemical carboxylation of cinnamyl bromide. Electrochemical carboxylation of various organic halides under optimum conditions gave the corresponding carboxylic acids, including ibuprofen and its precursor, in good yields. Advantages in the use of the fluidized electrochemical cell are that the electrochemical carboxylations can be carried out in higher yields and selectivities, and at higher current densities than those of the usual one-compartment cell.