Sulfoxidations Catalyzed by Baeyer-Villiger Monooxygenases

Cyclohexanone monooxygenase from Acinetobacter calcoaceticus NC3B 9871 is the most studied and applied BVMO. It has been demonstrated that this bacterial enzyme is an extremely versatile biocatalyst with an exceptionally broad substrate acceptance. CHMO.. has been employed in himdreds of oxida-tion procedures [26]. In fact, is a well known catalyst in the synthesis of 

has been used in the diastereoselective oxidation of different p-hydroxy sulfides to the corresponding chiral p-hydroxy sulfoxides. Chiral p-hydroxy sulfoxides represent interesting compounds used as chiral auxiliaries in asymmetric synthesis, asymmetric ligands, or as building blocks for the synthesis of cyclic sulfides, benzoxathiepines, allylic alcohols, or leukotrienes [27]. The sulfoxidation of these substrates is a kinetic resolution, in which both the sulfide and the sulfoxide can be obtained in chiral form. Oxidation of the cyclohexyl derivative (Table 6.1, entry 2) by a semipurified preparation of in the presence of the enzymatic 

TABLE 6.1 Asymmetric Synthesis of p-Hydroxy Sulfoxides Catalyzed by CHMO . ,  

BVMO-catalyzed sulfoxidahons have been performed mainly in aqueous media, due to the low stability of Yet, PAMO was shown to be very robust, and 

Another way of altering the substrate specificity of PAMO was shown in 2012 by creating some chimeric biocatalysts [38]. Thus, using structure-inspired subdomain exchange, PAMO was blend with CHMO. or steroid monooxygenase (STMO) from Rhodococcus rhodochrous. For this, 106 amino acids corresponding to the 

---