Polyethylene Glycol As a Recyclable Reaction Medium for Gold-Catalysed Direct Oxidative Amide Synthesis from Aldehydes and Amines

Polyethylene glycol (PEG) was used as the recyclable reaction medium for gold-catalysed oxidative amidation of aldehydes with amines by using tert-butyl hydroperoxide (TBHP, 70% aqueous) as the oxidant. The reaction proceeded efficiently to provide the corresponding products in moderate to good yields under mild conditions. Both the catalysts and solvent can be easily recovered and reused by simple extraction without significant loss of activity.