Electrochimica Acta, Vol.89, 692-699, 2013
Internal redox amidation of alpha,beta-unsaturated aldehydes in ionic liquids. The electrochemical route
A simple, N-heterocycliccarbene (NHC) activated synthesis of amides has been performed via electrolysis, carried out under galvanostatic control, of an ionic liquid (Bmim-BF4) followed by addition to the catholyte of an alpha,beta-unsaturated aldehyde and amine. Amides have been isolated, in good to elevated yields, in the absence of any base, co-catalyst and organic solvent. The selectivity of amidation, versus the formation of imine as by-product, has been related to the molar ratio electrogenerated NHC/aldehyde. The results, obtained using ionic liquids and electrochemical procedures, have been compared with those obtained using organic solvents and classical procedures. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:Amides;N-Heterocyclic carbenes;alpha,beta-Unsaturated aldehydes;Room temperature ionic liquids;Organic electrosynthesis