Asymmetric Oxidation and Carbene Transfer Reactions Catalyzed By Metalloporphyrins in Water
Catalytic enantioselective oxidations using transition-metal complexes are limited when the oxidant is hydrogen peroxide. The two main difficulties of using hydrogen peroxide in the presence of transition metal complexes are the homolytic cleavage generating OH radicals and the catalase reaction with formation of dioxygen. Asymmetric sulfoxidation, epoxidation of alkenes and hydroxylation catalyzed by iron and manganese porphyrins will be described (3). Thus the asymmetric epoxidation of styrene derivatives by H2O2 (or UHP) to give optically active epoxides (ee up to 81%) and hydroxylation of alkanes to give optically active secondary alcohols (ee up to 78%) were carried out in methanol and water using chiral water-soluble iron porphyrins as catalysts.
(1) Recent Advances in Catalysis by Water-Soluble Metalloporphyrins
G. Simonneaux, P. Le Maux, S. Chevance and H. Srour. Handbook of Porphyrin Science, 2012, Vol. 21, 377-410
(2) Enantioselective Manganese-Porphyrin-Catalyzed Epoxidation and C-H hydroxylation with Hydrogen Peroxide in Water/Methanol Solutions
H. Srour, P. Le Maux and G. Simonneaux. Inorg. Chem. 2012, 51, 5850-5856.
(3) Metal-catalyzed asymmetric sulfoxidation, epoxidation and hydroxylation by hydrogen peroxide
Hassan Srour, Paul Le Maux, Soizic Chevance, Gérard Simonneaux. Coord. Chem. Rev., 257 (2013) 3030– 3050