93183-66-5Relevant academic research and scientific papers
HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase
Tanaka, Koichi,Muraoka, Toshihide,Otubo, Yasuhiro,Takahashi, Hiroki,Ohnishi, Atsushi
, p. 21293 - 21301 (2016/03/08)
The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.
A click chemistry approach towards flavin-cyclodextrin conjugates-bioinspired sulfoxidation catalysts
Tomanová, Petra,?turala, Ji?í,Budě?ínsky, Milo?,Cibulka, Radek
, p. 19837 - 19848 (2015/12/23)
A click chemistry approach based on the reaction between alkynylflavins and mono(6-azido-6-deoxy)-β-cyclodextrin has proven to be a useful tool for the synthesis of flavin-cyclodextrin conjugates studied as monooxygenase mimics in enantioselective sulfoxi
Iron-catalyzed imidative kinetic resolution of racemic sulfoxides
Wang, Jun,Frings, Marcus,Bolm, Carsten
supporting information, p. 966 - 969 (2014/02/14)
Kinetic resolution of racemic sulfoxides requires either custom substrates or shows moderate enantioselectivity, leading to achiral coproducts (such as sulfones) as an intrinsic part of the process. A new strategy is demonstrated that allows the resolution of racemic sulfoxides through catalytic asymmetric nitrene-transfer reactions. This approach gives rise to both optically active sulfoxides and highly enantioenriched sulfoximines. By using a chiral iron catalyst and a readily available iodinane reagent, high selectivity factors have been achieved under very practical reaction conditions. With respect to the substrate scope, it is noteworthy that this unprecedented imidative kinetic resolution of racemic sulfoxides provides access to both aryl-alkyl and dialkyl sulfoximines in highly enantioenriched forms. Copyright
Activation of H2O2 by chiral confined Bronsted acids: A highly enantioselective catalytic sulfoxidation
Liao, Saihu,Coric, Ilija,Wang, Qinggang,List, Benjamin
supporting information; experimental part, p. 10765 - 10768 (2012/08/28)
Confined chiral Bronsted acids are shown to catalyze asymmetric oxidations of sulfides to sulfoxides with hydrogen peroxide. The wide generality and high enantioselectivity of the developed method compare even to the best metal-based systems and suggest utility in other asymmetric oxidations.
Aspergillus genus as a source of new catalysts for sulfide oxidation
Mascotti, Maria Laura,Orden, Alejandro A.,Bisogno, Fabricio R.,De Gonzalo, Gonzalo,Kurina-Sanz, Marcela
experimental part, p. 32 - 36 (2012/10/18)
This work extends the present knowledge about the ability of filamentous fungi to selectively transform sulfur-containing compounds. Here, it has been demonstrated that several species of the Aspergillus genus are able to perform chemo- and stereoselectiv
Exploring the biocatalytic scope of a bacterial flavin-containing monooxygenase
Rioz-Martinez, Ana,Kopacz, Malgorzata,De Gonzalo, Gonzalo,Torres Pazmino, Daniel E.,Gotor, Vicente,Fraaije, Marco W.
experimental part, p. 1337 - 1341 (2011/04/23)
A bacterial flavin-containing monooxygenase (FMO), fused to phosphite dehydrogenase, has been used to explore its biocatalytic potential. The bifunctional biocatalyst could be expressed in high amounts in Escherichia coli and was able to oxidize indole and indole derivatives into a variety of indigo compounds. The monooxygenase also performs the sulfoxidation of a wide range of prochiral sulfides, showing moderate to good enantioselectivities in forming chiral sulfoxides. The Royal Society of Chemistry 2011.
Turning a riboflavin-binding protein into a self-sufficient monooxygenase by cofactor redesign
De Gonzalo, Gonzalo,Smit, Christian,Jin, Jianfeng,Minnaard, Adriaan J.,Fraaije, Marco W.
supporting information; experimental part, p. 11050 - 11052 (2011/12/01)
By cofactor redesign, self-sufficient monooxygenases could be prepared. Tight binding of N-alkylated flavins to riboflavin-binding protein results in the creation of artificial flavoenzymes capable of H2O 2-driven enantioselective sulfoxidations. By altering the flavin structure, opposite enantioselectivities could be achieved, in accordance with the binding mode predicted by in silico flavin-protein docking of the unnatural flavin cofactors. The study shows that cofactor redesign is a viable approach to create artificial flavoenzymes with unprecedented activities.
Planar chiral flavinium salts - Prospective catalysts for enantioselective sulfoxidation reactions
Jurok, Radek,Cibulka, Radek,Dvorakova, Hana,Hampl, Frantisek,Hodacova, Jana
experimental part, p. 5217 - 5224 (2010/11/02)
A novel planar chiral flavinium salt, 3-benzyl-5-ethyl-10-(8- phenylnaphthalen-1-yl)isoalloxazinium perchlorate (2b), which bears a phenyl cap that covers one side of the isoalloxazinium skeleton plane, has been prepared as a potential catalyst for the enantioselective H2O2 oxidation of sulfides. The rate of H2O2 oxidation of sulfides in the presence of racemic 2b is comparable to that of the reaction catalysed by 5-ethyl-3,10-dimethylisoalloxazinium perchlorate, which indicates that the bulky shielding substituent does not influence the catalytic activity of the flavinium unit. The turnover frequency for the oxidation of thioanisole with hydrogen peroxide with 2b is 870 h-1. The enantiomerically pure salts (+)-2b and (-)-2b were prepared from the pure enantiomers (+)-3b and (-)-3b of 3-benzyl-10-(8-phenylnaphthalen-1-yl)isoalloxazine (3b) obtained by HPLC separation of racemic 3b on a chiral stationary phase. The enantiomerically pure salts (+)-2b and (-)-2b catalyse the H2O2 oxidation of para-substituted thioanisoles with enantiomeric excesses of 34-44%. The highest enantioselectivity (54% ee) was observed in the oxidation of methyl naphthyl sulfide.
Enzymatic synthesis of novel chiral sulfoxides employing Baeyer-villiger monooxygenases
Rioz-Martinez, Ana,De Gonzalo, Gonzalo,Pazmino, Daniel E. Torres,Fraaije, Marco W.,Gotor, Vicente
experimental part, p. 6409 - 6416 (2011/02/24)
Optically active sulfoxides are compounds of high interest in organic chemistry. Herein, we report the preparation of a set of chiral heteroaryl alkyl, cyclohexyl alkyl, and alkyl alkyl sulfoxides by using enantioselective sulfoxidation reactions employing three Baeyer-Villiger monooxygenases (BVMOs). Careful selection of the reaction conditions, starting sulfide, and biocatalyst can be used to achieve good to excellent enantiomeric excess values. Thus, valuable chiral synthons can be obtained by performing the reactions under mild and environmentally friendly conditions. The most promising biotransformations that employ a BVMO cell-free extract preparation have been developed on a 250-mg scale to give the chiral sulfoxides in high yields in most of the reactions. Copyright
Artificial metalloenzyme for enantioselective sulfoxidation based on vanadyl-loaded streptavidin
Pordea, Anca,Creusa, Marc,Panek, Jaroslaw,Duboc, Carole,Mathis, Deborah,Novic, Marjana,Ward, Thomas R.
experimental part, p. 8085 - 8088 (2009/02/01)
Nature's catalysts are specifically evolved to carry out efficient and selective reactions. Recent developments in biotechnology have allowed the rapid optimization of existing enzymes for enantioselective processes. However, the ex nihilo creation of catalytic activity from a noncatalytic protein scaffold remains very challenging. Herein, we describe the creation of an artificial enzyme upon incorporation of a vanadyl ion into the biotin-binding pocket of streptavidin, a protein devoid of catalytic activity. The resulting artificial metalloenzyme catalyzes the enantioselective oxidation of prochiral sulfides with good enantioselectivities both for dialkyl and alkyl-aryl substrates (up to 93% enantiomeric excess). Electron paragmagnetic resonance spectroscopy, chemical modification, and mutagenesis studies suggest that the vanadyl ion is located within the biotin-binding pocket and interacts only via second coordination sphere contacts with streptavidin.
