Direct electrochemical reduction of a bromo-propargyloxy ester at vitreous carbon cathodes in dimethylformamide
Direct electrochemical reduction of a bromo-propargyloxy ester at vitreous carbon cathodes in dimethylformamide
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DOI：
10.1016/j.jelechem.2003.07.011
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发表时间：
2003-12-15
影响因子：
4.5
通讯作者：
Peters, DG
中科院分区：
文献类型：
--
作者：
Esteves, AP;Goken, DM;Peters, DG
2-溴-3-（3 ′，4 ′-二甲氧基苯基）-3-（炔丙氧基）丙酸乙酯（1）在含有四烷基铵盐的二甲基甲酰胺中在玻碳电极上还原的循环伏安图显示三个显著波，对应于碳-溴键的断裂和反式-3-（3 ′，4 ′-二甲氧基苯基）-丙-2-烯酸乙酯（4）的随后还原。在对应于碳-溴键还原的电位下，1的控制电位电解提供4作为主要产物，平均产率为56%。在质子给体（1，1，1，3，3，3-六氟-2-丙醇）存在下，4的量略有减少，得到中等量（约26%）的2-（3 '，4'-二甲氧基苯基）-3-（乙氧羰基）-4-甲基-2，5-二氢呋喃（3）。我们提出了一个机制的计划，其中主要产品是通过一个和两个电子过程的组合形成的。(C)2003 Elsevier B. V.保留所有权利。
Cyclic voltammograms for the reduction of ethyl 2-bromo-3-(3', 4'-dimethoxyphenyl)-3-(propargyloxy)propanoate (1) at glassy carbon electrodes in dimethylformamide containing tetraalkylammoniurn salts exhibit three prominent waves corresponding to cleavage of the carbon-bromine bond and to subsequent reduction of ethyl trans-3-(3', 4'-dimethoxyphenyl)-prop-2-enoate (4). Controlled-potential electrolyses of 1 at potentials corresponding to reduction of the carbon-bromine bond afford 4 as the major product with an average yield of 56%. In the presence of a proton donor (1,1,1,3,3,3-hexafluoro-2-propanol), the quantity of 4 decreases slightly, and 2-(3',4'-dimethoxyphenyl)-3-(ethoxycarbonyl)-4-methyl-2,5-dihydrofuran (3) is obtained in moderate amount (similar to26%). We propose a mechanistic scheme whereby the major products are formed via a combination of one- and two-electron processes. (C) 2003 Elsevier B.V. All rights reserved.