Asymmetric Cyclopropanation of Olefins Catalyzed by a Chiral Cobalt(II) Porphyrin

Albrecht Berkessel, Erkan Ertürk and Jörg M. Neudörfl

Department für Chemie, Universität zu Köln, Greinstrasse 4, 50939 Köln, Germany

Abstract: The cobalt(II) complex of the Halterman porphyrin, 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-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.