R. Henderson, Nathan R. Buehler, Erick M. Pasciak
2014
Citations
0
Influential Citations
1
Citations
Journal
Journal of The Electrochemical Society
Abstract
Cyclic voltammograms for the reduction of ethyl 2-bromo-3-(3′,4′-dimethoxyphenyl)-3-(propargyloxy)propanoate (1) at a silver cathode in dimethylformamide (DMF) containing 0.10 M tetraethylammonium tetrafluoroborate (TEABF4) exhibit several cathodic peaks, the first of which is attributed to reductive cleavage of the carbon–bromine bond. Controlled-potential (bulk) electrolyses of 1 at silver gauze electrodes in DMF–0.10 M TEABF4 give rise to four products: cisand trans-isomers of ethyl 3-(3′,4′dimethoxyphenyl)-prop-2-enoate (4), ethyl 3-(3′,4′-dimethoxyphenyl)propiolate (7), and ethyl 3-(3′,4′-dimethoxyphenyl)-3-(prop2-yn-1-yloxy)propanoate (8). These products have been identified with the aid of mass spectrometry and nuclear magnetic resonance spectroscopy. We propose that reduction of 1 involves two-electron cleavage of the carbon–bromine bond to form a carbanion. Then the latter species eliminates −OCH2C≡CH to afford 4. In addition, −OCH2C≡CH can deprotonate 1 to yield (Z)-ethyl 2-bromo-3(3′,4′-dimethoxyphenyl)acrylate (5), which is further deprotonated by −OCH2C≡CH to give 7. Alternatively, the carbanion resulting from the original two-electron reduction of 1 can gain a proton from the medium to form 8. © The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0031501jes] All rights reserved.