A Phosphine-Catalyzed [3+2] Annulation Reaction of Modified Allylic Compounds and N-Tosylimines

A phosphine-catalyzed annulation of modified allylic ylides with various aromatic imines to form 3-pyrrolines was developed. The presence of a substituent in the allylic compound is crucial for this reaction. Without the substituent, (E)-dienylimines will be produced via the dimerization of the allylic compounds.