2788-86-5Relevant articles and documents
Green oxidation of olefins and methyl phenyl sulfide with hydrogen peroxide catalyzed by an oxovanadium(IV) Schiff base complex encapsulated in the nanopores of zeolite-Y
Rayati, Saeed,Salehi, Fatemeh
, p. 309 - 315 (2015)
Oxovanadium(IV) complex of a Schiff base ligand derived from 2,4-dihydroxyacetophenone and 2,2′-dimethylpropanediamine has been encapsulated in the nanopores of zeolite-Y by flexible ligand method and characterized by metal analysis, IR spectroscopic studies and X-ray diffraction patterns. The encapsulated complex [VOL-Y] catalyzes the oxidation of various olefins and methyl phenyl sulfide using hydrogen peroxide as a green oxidant in good yield. Under the optimized reaction conditions, in the presence of VOL-Y, 86 % conversion of cyclooctene with 100 % selectivity for epoxide and 51 % conversion for methyl phenyl sulfide with 92 % selectivity for sulfone were obtained.
A new clade of styrene monooxygenases for (R)-selective epoxidation
Xiao, Hu,Dong, Shuang,Liu, Yan,Pei, Xiao-Qiong,Lin, Hui,Wu, Zhong-Liu
, p. 2195 - 2201 (2021/04/12)
Styrene monooxygenases (SMOs) are excellent enzymes for the production of (S)-enantiopure epoxides, but so far, only one (R)-selective SMO has been identified with a narrow substrate spectrum. Mining the NCBI non-redundant protein sequences returned a new distinct clade of (R)-selective SMOs. Among them,SeStyA fromStreptomyces exfoliatus,AaStyA fromAmycolatopsis albispora, andPbStyA fromPseudonocardiaceaewere carefully characterized and found to convert a spectrum of styrene analogues into the corresponding (R)-epoxides with up to >99% ee. Moreover, site 46 (AaStyA numbering) was identified as a critical residue that affects the enantioselectivity of SMOs. Phenylalanine at site 46 was required for the (R)-selective SMO to endow excellent enantioselectivity. The identification of new (R)-selective SMOs would add a valuable green alternative to the synthetic tool box for the synthesis of enantiopure (R)-epoxides.
Diastereoselective Alkene Hydroesterification Enabling the Synthesis of Chiral Fused Bicyclic Lactones
Shi, Zhanglin,Shen, Chaoren,Dong, Kaiwu
, p. 18039 - 18042 (2021/11/16)
Palladium-catalysed diastereoselective hydroesterification of alkenes assisted by the coordinative hydroxyl group in the substrate afforded a variety of chiral γ-butyrolactones bearing two stereocenters. Employing the carbonylation-lactonization products as the key intermediates, the route from the alkenes with single chiral center to chiral THF-fused bicyclic γ-lactones containing three stereocenters was developed.
Production of enantiopure chiral epoxides with e. Coli expressing styrene monooxygenase
?tadániová, Radka,Fischer, Róbert,Gyuranová, Dominika,Hegyi, Zuzana,Rebro?, Martin
, (2021/06/15)
Styrene monooxygenases are a group of highly selective enzymes able to catalyse the epoxidation of alkenes to corresponding chiral epoxides in excellent enantiopurity. Chiral compounds containing oxirane ring or products of their hydrolysis represent key building blocks and precursors in organic synthesis in the pharmaceutical industry, and many of them are produced on an industrial scale. Two-component recombinant styrene monooxygenase (SMO) from Marinobacterium litorale was expressed as a fused protein (StyAL2StyB) in Escherichia coli BL21(DE3). By high cell density fermentation, 35 gDCW/L of biomass with overexpressed SMO was produced. SMO exhibited excellent stability, broad substrate specificity, and enantioselectivity, as it remained active for months and converted a group of alkenes to corresponding chiral epoxides in high enantiomeric excess (>95–99% ee). Optically pure (S)-4-chlorostyrene oxide, (S)-allylbenzene oxide, (2R,5R)-1,2:5,6-diepoxyhexane, 2-(3-bromopropyl)oxirane, and (S)-4-(oxiran-2-yl)butan-1-ol were prepared by whole-cell SMO.