Asymmetric cyclopropanation of olefins catalyzed by a chiral cobalt(II) porphyrin

The cobalt(II) complex of the Halterman porphyrin, 5,10,15,20-tetrakis[(1S, 4R, 5R, 8S)-1,2,3,4,5,6,7,8octahydro- 1,4: 5,8-dimethanoanthracene-9-yl] porphyrinato cobalt(II) [Co(por*)], was synthesized and its structure was identified by X-ray analysis. Up to 80: 20 trans: cis diastereomeric ratio and 82% ee were achieved in the cyclopropanation of styrene with ethyl diazoacetate by using this cobalt(II) porphyrin complex as catalyst