A group of functionalized oxazoles were synthesized in moderate to good yields from enamides via phenyliodine diacetate (PIDA)-mediated intramolecular cyclization. The main advantageous features of the present method include its broad substrate scope and the heavy-metal-free characteristic of the oxidative carbon-oxygen bond formation process.

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Synthesis of Oxazoles from Enamides via Phenyliodine Diacetate-Mediated Intramolecular Oxidative Cyclization. -This method yields highly functionalized oxazoles from readily available enamides. The usefulness of this method is demonstrated by a short total synthesis of oxaprozin (XIV) and analogues. -(ZHENG, Y.; LI, X.; REN, C.; ZHANG-NEGRERIE, D.; DU, Y.; ZHAO*, K.; J. Org. Chem. 77 (2012) 22, 10353-10361, http://dx.doi.org/10.1021/jo302073e ; Key Lab. Mod. Drug Delivery High-Effic., Sch. Pharm. Sci. Technol., Tianjin Univ., Tianjin 300072, Peop. Rep. China; Eng.) -Roessler 16-092

Expansion of 2H-Azirine Intermediates. -A direct one-pot method for the synthesis of isoxazoles from enaminones (I) is described through their PIDA-promoted cyclization to azirines followed by a previously reported FeCl2-catalyzed rearrangement. -(ZHENG, Y.; YANG, C.; ZHANG-NEGRERIE, D.; DU, Y.; ZHAO*, K.; Tetrahedron Lett. 54 (2013) 46, 6157-6160, http://dx.