Copper-Nitrene-Catalyzed Desymmetric Oxaziridination/1,2-Alkyl Rearrangement of 1,3-Diketones toward Bicyclic Lactams.

Although copper-nitrene has been extensively studied as a versatile active species in various transformations, asymmetric reactions involving copper-nitrene have been limited to the aziridination of olefins. Herein, we report the novel copper-nitrene-catalyzed desymmetric oxaziridination reaction of cyclic diketones with alkyl azides and the subsequent rearrangement of the resulting highly active intermediate, which produces a synthetically challenging chiral bicyclic lactam containing a quaternary carbon center. This procedure not only enriches the copper-nitrene-catalyzed asymmetric reactions, but also provides an alternative strategy to address the inherent challenges of catalytic asymmetric Schmidt reactions. This unique reaction could inspire the investigation of novel copper-nitrene-catalyzed asymmetric transformations and their reaction mechanisms.

Enantioselective organocatalytic oxaziridination of N-tosyl aldimine catalyzed by Cinchona alkaloid-ester derivatives.

A series of cinchona alkaloid-ester derivatives was synthesized and applied to catalyze the enantioselective oxaziridination of aryl aldimines with m-CPBA. The (R,R)-oxaziridines were obtained in good yields with high enantiomeric excess (ee) values (up to 98%).