Highly Diastereoselective Cyclopropanation of Olefins Catalysed By a C2-Symmetrical Chiral Iron Porphyrin Complex
Catalytic enantio- and diasteroselective olefin cyclopropanations  have been extensively explored and metal porphyrin complexes represent a very active and stereoselective class of catalysts. Some years ago we reported on the catalytic efficiency of chiral cobalt(II)-binaphthyl porphyrins in asymmetric cyclopropanations,  and recorded positive data encouraging us to synthesise the structurally related chiral porphyrin 1 and its iron(III) complex 2 (see figure). The catalytic activity of 2 in the asymmetric cyclopropanation of olefins by diazo compounds was investigated. Cyclopropanes were obtained with excellent yields (up to 99%), enantio- and diasteroselectivities (eetrans up to 80%, cis/trans ratios up to 99%). In addition to that, outstanding values of TON and TOF (20,000 and 120,000/h respectively) were achieved. 
 A. K. Kumar, Intern. J. Pharm. and Pharm. Sci. 2013, 5, 467-472.
 D. Intrieri, A. Caselli and E. Gallo, Eur. J. Inorg. Chem. 2011, 5071-5081.
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