Mj. Sodergren et al., READILY AVAILABLE NITRENE PRECURSORS INCREASE THE SCOPE OF EVANS ASYMMETRIC AZIRIDINATION OF OLEFINS, Tetrahedron : asymmetry, 8(21), 1997, pp. 3563-3565
The performance of the copper-catalyzed asymmetric aziridination of ol
efins is highly dependent on the properties of the nitrene precursor.
Our preliminary results show significant improvements of both enantios
electivity and chemical yields when [N-(4-nitrobenzenesulfonyl)imino]
phenyliodinane 1b (p-NO2C6H4SO2N=IPh) is employed instead of the commo
nly used p-tolyl analog 1a (PhI=NTs). This paper reports the compariso
n of some nitrene precursors for the copper-catalyzed asymmetric aziri
dination of olefins, utilizing the olefin as the limiting component an
d 1.5 equivalents of the nitrene precursor. The aziridine derivatives
of several olefins were obtained in moderate to excellent yields and w
ith enantioselectivity up to 95% ee. (C) 1997 Elsevier Science Ltd.