Bromotriphenylphosphonium Salt Promoted Tandem One‐Pot Cyclization to Optically Active 2‐Aryl‐1,3‐oxazolines

Abstract

Optically active 2‐aryl‐1,3‐oxazolines, such as aromaticcarbocycles, heterocycle‐binding 4‐benzyl (or phenyl)‐1,3‐oxazolines and their 5‐benzyl (or phenyl)‐1,3‐oxazoline isomers were successfully prepared through a bromotriphenylphosphonium salt promoted aziridine ring formation and ring opening sequential process involving tandem one‐pot cyclization of chiral 2‐amino‐3‐phenylpropanol or 2‐amino‐2‐phenylethanol with various aromatic acids in toluene at 90 °C in moderate to excellent yields. The mechanism of this tandem process was also substantiated experimentally.