有机化学 ›› 2020, Vol. 40 ›› Issue (11): 3873-3880.DOI: 10.6023/cjoc202006071 上一篇    下一篇

研究论文

以氨气为氢源的电化学烯丙位氢化脱氟反应研究

盛杰a, 吴娜a, 刘旭a, 刘峰a, 刘帅a, 丁伟杰a, 刘畅a, 程旭a,b   

  1. a 南京大学化学化工学院 江苏省先进有机材料重点实验室 化学与生物医学科学研究所 南京 210023;
    b 南开大学 元素有机化学国家重点实验室 天津 30071
  • 收稿日期:2020-06-29 修回日期:2020-07-23 发布日期:2020-08-06
  • 通讯作者: 程旭 E-mail:chengxu@nju.edu.cn
  • 基金资助:
    国家自然科学基金(No.22071105,22031008)、江苏省教育厅青蓝工程和国家重点研发计划(No.2019YFC0408303)资助项目.

Electrochemical Allylic Hydrodefluorination Reaction Using Gaseous Ammonia as Hydrogen Source

Sheng Jiea, Wu Naa, Liu Xua, Liu Fenga, Liu Shuaia, Ding Weijiea, Liu Changa, Cheng Xua,b   

  1. a Institute of Chemical and Biomedical Science, Jiangsu Advanced Organic Material Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023;
    b State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071
  • Received:2020-06-29 Revised:2020-07-23 Published:2020-08-06
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 22071105, 22031008), the QingLan Project of Jiangsu Education Department and the National Key Research and Development Program of China (No. 2019YFC0408303).

偕位二氟烯烃在药物设计及含氟分子构建等方面都有广泛的应用.其电化学合成研究的开展有限,主要集中于利用三氟甲酮的脱氟烯醇硅醚化反应.利用β-三氟甲基肉桂酸酯的烯丙位氢化脱氟制备偕二氟烯烃的方法简单直接,但相关报道有限.利用电化学方法,以氨气为氢源,以石墨毡为阴阳极材料,实现了一系类的β-三氟甲基肉桂酸酯电化学烯丙位氢化脱氟反应,以中等到优秀的收率获得了多种α-取代偕二氟苯乙烯类化合物.反应中氨气与石墨毡阴极的组合可以高效地抑制阴极析氢的反应,确保阴极向底物的电子转移的高选择性.循环伏安和方波伏安实验表明反应是经历分步的电子转移过程,从而实现C—H键的形成以及C—F的断裂.

关键词: 电化学, 氨气, C—F键活化, 石墨毡电极

gem-Difluoroalkenes have wide applications in the drug designs and act as the synthon of molecules containing fluoride. The current researches on the electrochemical syntheses of gem-difluoroalkenes are limited to the silylation of enolated trifluoromethyl ketones. Herein, by using graphite felt as electrodes, the electrochemical allylic hydrodefluorination of α-trifluoromethyl cinnamates is realized using gaseous ammonia as hydrogen source, giving gem-difluorostyrenes in moderate to good yields. The usage of ammonia and graphite felt cathode is important to inhibit the cathodic hydrogen evolution, keeping the electron transfer from cathode to substrate with high selectivity. The cyclic voltammetry (CV) and square wave voltammetry (SWV) analyses support a stepwise electron transfer process to achieve the C—H bond formation and C—F bond cleavage.

Key words: electrochemistry, ammonia, C-F bond activation, graphite felt electrode