Gold-Catalyzed Oxidative Cyclization of Chiral Homopropargyl Amides: Synthesis of Enantioenriched γ-Lactams

A gold-catalyzed tandem cycloisomerization/oxidation of homopropargyl amides has been developed, which provides ready access to synthetically useful chiral gamma-lactams with excellent ee by combining the chiral tert-butylsulfinimine chemistry and gold catalysis. The utility of this methodology has also been demonstrated in the synthesis of biologically active compound S-MPP and natural product (-)-bgugaine. The use of readily available starting materials, a simple procedure, and mild reaction conditions are other significant features of this method.