An efficient and concise approach for the synthesis of 2,4,6-triphenyl pyridines has been developed through copper-catalysed oxidative decarboxylativecoupling of C(sp3) aryl acetic acids with oxime acetates in DMF at 150 °C under an oxygen atmosphere. Various functional groups were well tolerated and provided the corresponding 2,4,6-triphenyl pyridines in good to excellent yields.
An efficient procedure for the synthesis of 2,4,6-triarylpyridines (Krohnke pyridines) by the one-pot multicomponent condensation of aldehydes (1 equiv) with acetophenones (2 equiv) and ammonium acetate (1.2 equiv) in the presence of catalytic amounts of oxozirconium(IV) chloride (ZrOCl2) under solvent-free conditions is described. In this work, four products have been reported for the first time.