Synthesis of 2,4,5-vinylic-trisubstituted oxazoles via a Palladium-catalyzed cascade coupling reaction

A novel cascade coupling approach to the assembly of 2,4,5-vinyl-trisubstituted oxazoles is described. This reaction employs readily accessible β,β-dibrominated secondary enamides and terminal alkenes , and proceeds via a ligand-free Pd-catalyzed cascade C O coupling/Heck reaction. A novel one-step synthesis of valuable 2,4,5-vinylic-trisubstituted oxazoles is described. This reaction, utilizing readily available β,β-dibrominated secondary enamides and terminal alkenes as starting materials, occurs via a ligand-free Palladium-catalyzed cascade intramolecular C O coupling/intermolecular Heck reaction .