Peng Du, D. Peters
Nov 1, 2010
Citations
0
Influential Citations
6
Citations
Journal
Journal of The Electrochemical Society
Abstract
Studies of the electrochemical reductions of 1-(2-chloroethyl)-2-nitrobenzene (1) and 1-(2-bromoethyl)-2-nitrobenzene (2) at carbon cathodes in dimethylformamide (DMF) containing tetramethylammonium tetrafluoroborate (TMABF 4 ) have been undertaken. Cyclic voltammograms for 1 and 2 exhibit three irreversible cathodic peaks, the first of which is attributed to one-electron reduction of the nitro group, and the resulting nitro radical-anion immediately reacts as a base with the adjacent alkyl halide moiety via an E2 elimination to produce 1-nitro-2-vinylbenzene. At a potential corresponding to the first cathodic peak, bulk electrolyses of 1 or 2 in the absence of a proton donor afford 1-nitro-2-vinylbenzene as principal product, along with 1H-indole and a dimeric species. However, when 1 or 2 is electrolyzed in the presence of either phenol or 2,4-pentanedione as a proton source, the only significant product is 1H-indole. A mechanistic picture for the reductions of 1 and 2 is proposed, and a separate examination of the electrochemical behavior of 1-nitro-2-vinylbenzene has been included as part of this work.