F. Pragst, A. Henrion, W. Abraham
1987
Citations
0
Influential Citations
5
Citations
Journal
Journal Fur Praktische Chemie-chemiker-zeitung
Abstract
The electrochemical reduction of some N-acylamino-, N-amino-, N-benzyl- and N-phenacyl-substituted pyridinium and triazolium ions is investigated in acetonitrile by voltammetric methods and potentiostatic electrolyses. The acylaminopyridinium ions 1 and the arylaminopyridinium ions 3 are cathodically cleaved into the pyridine derivative and the carboxylic amide or the aromatic amine. In the case of the 1-benzyl-4-acylaminotriazolium ions 5 the reductive formation of hydrogen from the acidic N-acylamino group is preferred and the corresponding ylide is formed, which reacts at more negative potential by splitting off the benzyl group. The reduction of the N-phenacylpyridinium ion 7d occurs with splitting off the phenacyl radical, which dimerizes to 1,2-dibenzoylethane in a good yield. In the case of N-benzyl- and N-p-cyanobenzylpyridinium ions the cathodic dimerization to the corresponding bisdihydropyridines was found, whereas the electrolysis of the N-nitrobenzylpyridinium ions occurs with cleavage of the N-substituent-bond, which is initiated by the primary formation of the nitrophenyl anion radical. It follows from electrogenerated chemiluminescence experiments that the cleavage of the cations 1 and 5 occurs with the uptake of one electron.