Facile, selective, and regiocontrolled synthesis of oxazolines and oxazoles mediated by ZnI2 and FeCl3.

An expedient method for a direct approach to the selective and regiocontrolled synthesis of 2-oxazolines and 2-oxazoles mediated by ZnI(2) and FeCl(3) is described. A Lewis acid promoted cyclization of acetylenic amide with various functionalities was well tolerated to give 2-oxazolines and 2-oxazoles in good to excellent yields under mild reaction conditions.