| Autor: |
Caselli, Alessandro, Gallo, Emma, Fantauzzi, Simone, Morlacchi, Simona, Ragaini, Fabio, Cenini, Sergio |
| Zdroj: |
European Journal of Inorganic Chemistry; July 2008, Vol. 2008 Issue: 19 p3009-3019, 11p |
| Abstrakt: |
CoIItpp catalyzes the reaction of aromatic azides ArN3 with nonactivated olefins to yield allylic amines or aziridines in moderatetogood yields. The chemoselectivity of the catalytic reaction is particularly high. Depending on the substrate employed, allylic amines or aziridines can be obtained. The reaction mechanism was investigated, and the reaction proceeds through reversible coordination of the aryl azide to the CoII–porphyrin complex. The often postulated “nitrene” complex is not an intermediate in this reaction. The kinetics for the allylic amination is first order in azide, Cotpp, and olefin. For the aziridination, the kinetics is again first order in azide and catalyst, but we observed a firstorder dependence of the rate on αmethylstyrene only up to an olefin concentration of 6.9 M. An inhibiting role of the competitively formed 14nitrophenyl5methyl5phenyl1,2,3triazoline was identified. The triazoline was shown to reversibly coordinate to Cotpp, which blocks the free coordination site necessary for the catalytic reaction to proceed, and is it responsible for the catalyst deactivation in the aziridination reaction of αmethylstyrene by 4nitrophenyl azide. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008 |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Plný text