Copper(II) Acetate-Catalysed Conversion of Aldoximes to Amides under Mild Conditions

Abstract

A mild method for the metal-catalysed conversion of aldoximes to amides has been achieved by the combined use of copper(II) acetate and MeCN in EtOH under reflux. The presence of a catalytic amount of MeCN (0.05 equiv.) accelerated the reaction and improved the yield. Aryl, heteroaryl and alkyl aldoximes were transformed into the corresponding amides in moderate to good yield. 2-Furyl and 2-thiophenyl aldoximes, which possess a heteroatom lone pair positioned ortho to the oximido group, showed enhanced reactivity, and the corresponding amides were obtained in excellent yield.

Cu(OAc)2/Malononitrile/Water: A Simple Reaction System for Synthesis of Aromatic Nitriles from Aldoximes

“…Usually, this conversion is achieved either via the dehydration of aldoximes using various dehydration reagents such as acid anhydrides, 1 thionyl chloride and its derivatives, 2 acids, 3 phosphorus-containing compounds, 4 or by treating aldoximes with a variety of metal catalysts, our interest being in copper salts. [5][6][7][8][9][10][11] Recently we reported the preparation of aromatic and heterocyclic nitriles by treating the corresponding aldehydes with hydroxylamine and CuO in refluxing MeCN. 12 We now report an improved method in which the oximes are not formed in situ but are used as starting materials and malononitrile replaces acetonitrile, Cu(OAc) 2 replaces CuO and water is the solvent.…”