Catalytic Oxidations of Steroid Substrates by Artificial Cytochrome P-450 Enzymes

Catalysts comprising manganese-porphyrins carrying cyclodextrin binding groups are able to perform hydroxylations with substrate selectivity and regio- and stereoselectivity and high catalytic turnovers. The geometries of the catalyst/substrate complexes override intrinsic substrate reactivities, permitting attack on geometrically accessible saturated carbons of steroids in the presence of secondary carbinol groups and carbon-carbon double bonds, as in enzymatic reactions. Selective hydroxylations of steroid carbon 9 positions are of particular practical interest.