Iodine(III)-Promoted Synthesis of Oxazoles through Oxidative Cyclization of N-Styrylbenzamides
摘要:
The hypervalent iodine reagent PhI(OTf)(2), generated in situ, has been successfully utilized in an intramolecular oxidative cyclization of N-styrylbenzamides. In remarkably short reaction times, the desired 2,5-disubstituted oxazoles were isolated in high yields in this metal-free oxidative C-O bond-forming reaction.
A general synthesis of N-styrylamides starting from amides and phenylacetaldehyde is described. Condensation of the amide, aldehyde and benzotriazole affords N-(1-benzotriazol-1-yl-2-phenylethyl)amides 2 from which the benzotriazole molecule is smoothly eliminated.