Bromoporphyrins as Versatile Synthons for Modular Construction of Chiral Porphyrins: Cobalt-Catalyzed Highly Enantioselective and Diastereoselective Cyclopropanation.

This article focuses on bromoporphyrins. Metalloporphyrins have been found to catalyze a range of fundamentally and practically important chemical transformations, some of which represent the first demonstrations of such catalytic processes. Due to the unique ligand environment and metal coordination mode, unusual reaction selectivities and excellent catalyst turnovers have been observed for metalloporphyrin-based catalysts. Although significant progress has been made, catalytic reactions based on metalloporphyrins have not been developed into practical methodologies that can be used in asymmetric synthesis.