ASYMMETRIC SULFOXIDATION CATALYZED BY A VANADIUM-CONTAINING BROMOPEROXIDASE

A vanadium-containing bromoperoxidase (VBrPO) from the alga Corallina officinalis has been shown to catalyze the stereoselective oxidation o f some aromatic bicyclic sulfides to the corresponding (S)-sulfoxides in high (up to 91%) ee. Hydrogen peroxide was found to have a large ef fect on the catalyzed reaction, most likely due to an inhibition of VB rPO. High optical and chemical yields were found to be favored by a co ntinuous slow addition of hydrogen peroxide to keep a low excess. The reaction gives no overoxidation to sulfone, and its stereochemistry is the opposite as compared to that previously found with the heme-conta ining chloroperoxidase (CPO) from Caldariomyces fumago.