Effects of Electrolyte, Current Density and Electricity Consumption on the Anodic Oxidation of Cyclic Amides
Anodic oxidation of N-alkylamides in the presence of nucleophiles such as water, alcohol or carboxylic acid, affords the respective alpha- hydroxy, -alkoxy or -carboxy derivatives as final products (Eq. 1).
The electrochemical properties of three cyclic amides of the type N-acylazacycloalkanes (I - III) (Scheme 1) have been investigated in acetonitrile by cyclic voltammetry. Each one of them exhibits one irreversible anodic wave (at ~2 V) and one irreversible cathodic wave (at around -1.3 V).
Preparative anodic oxidation of I - III in methanol at C anodes under various electrochemical conditions (current density, electricity consumption and supporting electrolytes) led to four major products by all three substrates: alpha-methoxy- and alpha,alpha'-dimethoxy cyclic amides, and two cyclic eneamide derivatives. Their relative ratio was found to be highly dependent on the nature of the electrolyte and current density.
 E. Steckhan in Organic Electrochemistry (H. Lund, M.M. Baizer, Eds.), 3rd Ed., Chap. 15, pp. 601-607, Marcel Dekker, New York, 1990.
 T. Golub and J. Y. Becker, J. Electrochem. Soc., 2013, 160 (7), G1-G5.