Metal-Free Bacterial Haloperoxidases as Unusual Hydrolases: Activation of H_2O_2 by the Formation of Peracetic Acid

摘要

Haloperoxidases catalyze the formation of hypohalites from hydrogen peroxide and chloride, bromide, or iodide [Eq (1)]. The electrophiles thus formed are able to halogenate suitable organic substrates and can thus play an important role in the biosynthesis of halogenated natural products. Haloperoxidases can also catalyze the transfer of oxygen from hydrogen peroxide to. organic substrates such as olefins or thioethers. Therefore, this class of enzymes has been intensively studied with respect to preparative transformations, for example, the asymmetric epoxidation of olefins and sulfbxidation of thioethers. Furthermore, hydrogen peroxide is a readily available, mild, and environmentally friendly terminal oxidant.