Iodine(III)-promoted synthesis of oxazolines from N-allylamides

PhI(OAc)2 (activated by BF3·OEt2) has been used to promote the oxidative cyclization of N-allylamides to give oxazolines. The reaction products are formed in high yield and, when a branched allylic amine is used, high diastereoselectivity. Initial mechanistic experiments suggest that the final C–O bond is formed from a reactive tight ion pair, rather than a neutral external nucleophile.