Peroxygenase-Catalyzed Enantioselective Sulfoxidations

The performances of the unspecific peroxigenase from Agrocybe aegerita (AaeUPO) in the asymmetric sulfoxidation of substituted aryl alkyl sulfides were here investigated. A small library of differently substituted aryl alkyl sulfoxides was successfully synthesized from the corresponding sulfides in the presence of AaeUPO and H2O2. All the sulfoxides were obtained as (R)-enantiomers, regardless the substitution pattern both on the aromatic ring and the alkyl chain, in up to > 99 % conversion and > 99 % ee. An overview about the biocatalytic entries to chiral sulfoxides is also presented here in form of a comparison between the results obtained with AaeUPO and performances of the chloroperoxidase from Caldariomyces fumago, and three different Baeyer–Villiger monooxygenases. To the best our knowledge, this is the first example of a systematic investigation of the AaeUPO synthetic potential in the asymmetric oxidation of hetero atoms, i.e., the pro-stereogenic sulfur of sulfides.