By a targeted enzyme engineering approach, we were able to create an efficient NADPH oxidase from a monooxygenase. Intriguingly, replacement of only one specific single amino acid was sufficient for such a monooxygenase-to-oxidase switch-a complete transition in enzyme activity. Pre-steady-state kinetic analysis and elucidation of the crystal structure of the C65D PAMO mutant revealed that the mutation introduces small changes near the flavin cofactor, resulting in a rapid decay of the peroxyflavin intermediate. The engineered biocatalyst was shown to be a thermostable, solvent tolerant, and effective cofactor-regenerating biocatalyst. Therefore, it represents a valuable new biocatalytic tool.

This paper reports a comparative study of the chemoselectivity and yields of the synthesis of N-alkyl-4-(trihalomethyl)-1H-pyrimidin-2-ones carried out by the cyclocondensation of 4-alkoxy-1,1,1-trihalo-3-alken-2-ones (enones) with methyland allylureas with the N-alkylation of 4-(trihalomethyl)-1H-pyrimidin-2-ones with methyl iodide and allyl bromide. To determine the chemoselectivity of the products obtained, all compounds were fully analyzed by 1 H and 13 C NMR and 2D HMBC spectroscopy. This study has demonstrated that the

S y n t h e s i s o f S o m e N o v e l P y r i m i d o [ 1 , 2 -a ] b e n z i m i d a z o l e sAbstract: The synthesis of some potentially active 2-(trifluoromethyl)pyrimido[1,2-a]benzimidazoles and pyrimido[1,2-a]benzimidazol-2(1H)-ones by the cyclization of 4-alkoxyvinyl trifluoro(chloro)methyl ketones with 2-aminobenzimidazole is described. The structure of the products was assigned based on 1 H and 13 C NMR as well as 2D-NMR experiments. Some of the obtained products exhibited significant DNA-topoisomerase I inhibitory activity.

The applicability of Baeyer–Villiger monooxygenases (BVMOs) in organoboron chemistry has been explored through testing chemo‐ and enantioselective oxidations of a variety of boron‐containing aromatic and vinylic compounds. Several BVMOs, namely: phenylacetone monooxygenase (PAMO), M446G PAMO mutant, 4‐hydroxyacetophenone monooxygenase (HAPMO) and cyclohexanone monooxygenase (CHMO) were used in this study. The degree of chemoselectivity depends on the type of BVMO employed, in which the biocatalysts prefer boron‐carbon oxidation over Baeyer–Villiger oxidation or epoxidation. Interestingly, it was discovered that PAMO can be used to perform kinetic resolution of boron‐containing compounds with good enantioselectivities. These findings extend the known biocatalytic repertoire of BVMOs by showing a new family of compounds that can be oxidized by these enzymes.

a b s t r a c tThe synthesis of chiral-centered selenium compounds is presented. Enantioselective oxidations of these organoselenium compounds were performed using a wide range of biocatalysts, including BaeyereVilliger monooxygenases, oxidoreductases-containing Aspergillus terreus and lipase (Cal-B) in the presence of oxidants. Finally, efficient synthesis of enantiopure organoselenium compounds using a kinetic resolution approach mediated by Cal-B was achieved.