Mechanism of Cobalt-Porphyrin–Catalyzed Aziridination

Density functional theory (DFT; OLYP) calculations clearly indicate the involvement of a cobalt nitrene in cobalt-porphyrin–catalyzed alkene aziridinations, as well as in allylic aminations. The transition state for the cobalt-nitrene–alkene interaction may be described as triradicaloid. A subsequent carbon radical, if it exists at all as an intermediate, collapses in an essentially barrierless manner to the aziridine product.