A modular and practical synthesis of highly substituted oxazoles has been developed. The transformation consists of a sequential copper-catalyzed amidation of vinyl halides followed by cyclization promoted by iodine. A wide variety of functionalized oxazoles and polyazoles can be obtained in a selective manner from simple and easily accessible precursors.
“Sequential Copper-Catalyzed Vinylation/Cyclization: An Efficient Synthesis of Functionalized Oxazoles”, Org. Lett., 2007, 9(26), 5521-5524.