A novel Pd-catalyzed/Cu-mediated oxidativecyclization has been developed for the synthesis of trisubstituted oxazoles, which is thought to proceed through cascade formation of C-N and C-O bonds. In this protocol, four hydrogen atoms were removed and water was used as the oxygen atom source.
A novel palladium-catalyzed approach for constructing 2,5-diarylated oxazole-4-carboxylates using sodium arylsulfinates as the aryl source has been demonstrated.