Facile route to benzils from aldehydes via NHC-catalyzed benzoin condensation under metal-free conditions

A simple and efficient one-pot procedure for the synthesis of alpha-diketones from aldehydes via benzoin condensation under the influence of a catalytic amount of azolium salt combined with DBU has been developed. Thus, aldehyde was allowed to react with the azolium salt/DBU catalytic system at room temperature, and then the reaction mixture was heated to 70 degrees C under air atmosphere to afford the corresponding 1,2-diketone in good yield. This would be an efficient alternative method of synthesizing alpha-diketones from alclehydes under metal-free conditions. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.