Phosphine-Catalyzed [3+2] Annulation of β-Sulfonannido-Substituted Enones with Sulfamate-Derived Cyclic Imines

Phosphine-catalyzed [3+2] annulation of beta-sulfonamido-substituted enones and sulfamate-derived cyclic imines has been developed, giving a series of imidazoline derivatives in moderate to excellent yields with good to excellent diastereoselectivities. A scale-up reaction worked well under mild reaction conditions. A possible mechanism was proposed on the basis of the results obtained.