Enantioselectivity in Enzyme-Catalyzed Electron Transfer to and from Planar Chiral Organometallic Compounds

Unnatural substrates (ferrocenes) with unnatural chirality type (planar chirality) are kinetically recognized by horseradish peroxidase (HRP), but not by chloroperoxidase (CLP), in one-electron HRP- and CLP-catalyzed oxidation of (S)- and (R)-2-methylferrocene carboxylic acid (1, right) into the corresponding ferricenium cations. The enzymatic reduction of (S)-1+ and (R)-1+ by reduced glucose oxidase (GO) is also enantioselective.