Synthesis of Enantioenriched Pyrrolidines via Gold-Catalyzed Tandem Cycloisomerization/Hydrogenation of Chiral Homopropargyl Sulfonamides

A novel gold-catalyzed tandem cycloisomerization/hydrogenation of chiral homopropargyl sulfonamides has been developed. Various enantioenriched pyrrolidines can be obtained in excellent yields and excellent enantioselectivities by combination of chiral tert-butylsulfinimine chemistry with gold catalysis. Importantly, this represents the first example of a pyrrolidine synthesis from homopropargyl sulfonamide.