Cyclopropanation Reactions Mediated by Group 9 Metal Porphyrin Complexes

The one-pot reaction of diazo compounds with olefins represents a useful strategy to synthesise cyclopropanes, which are important both as starting materials for the synthesis of organic compounds and because of their intrinsic pharmaceutical properties. Herein we describe the catalytic activity of group 9 metal porphyrin complexes to cyclopropanate olefins that present different electronic behaviour. All the most important porphyrin-based methodologies have been reviewed, stressing the stereocontrol of the reactions achieved in each case. Moreover, mechanism investigations have provided data that can help greatly to elaborate more efficient catalytic systems in the future.