Readily available nitrene precursors increase the scope of Evans' asymmetric aziridination of olefins

Article abstract of DOI:10.1016/S0957-4166(97)00496-5

The performance of the copper-catalyzed asymmetric aziridination of olefins is highly dependent on the properties of the nitrene precursor. Our preliminary results show significant improvements of both enantioselectivity and chemical yields when [N-(4-nitrobenzenesulfonyl)imino]phenyliodinane 1b (p-NO₂C₆H₄SO₂N=IPh) is employed instead of the commonly used p-tolyl analog 1a (PhI=NTs). This paper reports the comparison of some nitrene precursors for the copper-catalyzed asymmetric aziridination of olefins, utilizing the olefin as the limiting component and 1.5 equivalents of the nitrene precursor. The aziridine derivatives of several olefins were obtained in moderate to excellent yields and with enantioselectivity up to 95% ee.