Soluble Cu(I) and Cu(II) triflate and perchlorate salts are efficient catalysts for the aziridination of olefins employing (N-(p-tolylsulfonyl)imino)phenyliodinane PhI=NTs, as the nitrene precursor. Electron-rich as well as electron-deficient olefins undergo aziridination with this reagent in 55-95% yields, at temperatures ranging from -20 degrees C to +25 degrees C. The catalyzed nitrogen atom-transfer reaction to enol silanes and silylketene acetals has also been developed to provide facile syntheses of alpha-amino ketones. Other metal complexes were found to be less effective at catalyzing the reaction, while PhI=NTs proved to be superior to other imido group donors as the nitrene precursor. Reaction rates and yields are enhanced in polar aprotic solvents such as MeCN and MeN0(2). Reaction stereospecificity in the aziridination of cis and trans disubstituted olefins was evaluated and found to be both catalyst and substrate dependent. Intermolecular competition experiments between pairs of mono- and disubstituted olefins indicate that the olefin selectivity profile for the reaction is independent of the oxidation state of the copper catalyst employed. It is concluded that these reactions are proceeding through the 2+ catalyst oxidation state under the conditions employed in this study.