55494-06-9Relevant academic research and scientific papers
Biocatalytic Oxidative Cascade for the Conversion of Fatty Acids into α-Ketoacids via Internal H2O2 Recycling
Gandomkar, Somayyeh,Dennig, Alexander,Dordic, Andela,Hammerer, Lucas,Pickl, Mathias,Haas, Thomas,Hall, Mélanie,Faber, Kurt
supporting information, p. 427 - 430 (2018/02/21)
The functionalization of bio-based chemicals is essential to allow valorization of natural carbon sources. An atom-efficient biocatalytic oxidative cascade was developed for the conversion of saturated fatty acids to α-ketoacids. Employment of P450 monooxygenase in the peroxygenase mode for regioselective α-hydroxylation of fatty acids combined with enantioselective oxidation by α-hydroxyacid oxidase(s) resulted in internal recycling of the oxidant H2O2, thus minimizing degradation of ketoacid product and maximizing biocatalyst lifetime. The O2-dependent cascade relies on catalytic amounts of H2O2 and releases water as sole by-product. Octanoic acid was converted under mild conditions in aqueous buffer to 2-oxooctanoic acid in a simultaneous one-pot two-step cascade in up to >99 % conversion without accumulation of hydroxyacid intermediate. Scale-up allowed isolation of final product in 91 % yield and the cascade was applied to fatty acids of various chain lengths (C6:0 to C10:0).
Synthesis of trimethylsilyl carboxylates by HMDS under solvent-free conditions
Jereb, Marjan,Lakner, Janja
supporting information, p. 5713 - 5723 (2016/08/23)
A broad set of structurally different carboxylic acids were transformed into their trimethylsilyl esters with HMDS in a practically completely solvent-free process, while a catalytic amount of iodine was required in some cases. The process has several advantages over the known methods: untreated reactants, air atmosphere, mild and neutral conditions, no evolution of hydrogen halide, no need of an additional base, low amount of waste, completely without chromatography, low consumption of energy, and operational simplicity.
Fe(TAML)Li/(diacetoxyiodo)benzene-mediated oxidation of alcohols: Evidence for mild and selective C-O and C-C oxidative cleavage in lignin model transformations
Napoly, Francois,Jean-Gerard, Ludivine,Goux-Henry, Catherine,Draye, Micheline,Andrioletti, Bruno
, p. 781 - 787 (2014/03/21)
A novel combination of Fe(TAML)Li and (diacetoxyiodo)- benzene for the oxidation of primary and secondary alcohols at 25 °C in acetone is reported. In view of the interesting ability of this system to selectively cleave specific types of C-C bonds of elaborated alcohols, the application of this novel combination to the oxidative cleavage of lignin model molecules was investigated. Considering the numerous supported versions of the oxidant as well as the mild conditions employed, the developed methodology appears to be a promising lignin depolymerization strategy.
Partition coefficients of ketones, phenols, aliphatic and aromatic acids, and esters in n-hexane/nitromethane
Kotowska, Urszula,Isidorov, Valery A.
scheme or table, p. 813 - 824 (2012/03/27)
Liquid-liquid partition is used in sample preparation and in countercurrent and liquid-liquid chromatographic separations. Partition coefficients are widely used in toxicology, environmental, and analytical chemistry. The K hn determination procedure for the n-hexane/ nitromethane system was optimized and partition coefficients for 99 ketones, esters and trimethylsilyl derivatives of phenols, aliphatic and aromatic acids were determined. For 130 compounds, Khn values were predicted using mathematical relationships between Khn and other physicochemical and structural parameters. Versita Sp. z o.o.
Identification of products containing -COOH, -OH, and -C=O in atmospheric oxidation of hydrocarbons
Yu, Jianzhen,Flagan, Richard C.,Seinfeld, John H.
, p. 2357 - 2370 (2007/10/03)
Atmospheric oxidation of hydrocarbons by hydroxyl radicals and ozone leads to products containing -COOH, -OH, and -C=O functional groups. The high polarity of such compounds precludes direct GC-MS analysis. In addition, many such compounds often exist in a single sample at trace levels. An analytical method has been developed to identify compounds containing one or more functional groups of carbonyl, carboxy, and hydroxy in atmospheric samples. In the method, -C=O groups are derivatized using O-(2,3,4,5,6- pentafluorobenzyl) hydroxy amine (PFBHA), and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)- trifluoroacetamide (BSTFA). The derivatives are easily resolved by a GC column. The chemical ionization mass spectra of these derivatives exhibit several pseudomolecular ions, allowing unambiguous determination of molecular weights. Functional group identification is accomplished by monitoring the ions in the electron ionization mass spectra that are characteristic of each functional group derivative: m/z 181 for carbonyl and m/z 73 and 75 for carboxyl and hydroxy groups. The method is used to identify products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene. Among products from ozone oxidation of α-pinene, we have detected pinonaldehyde, norpinonaldehyde, pinonic acid, norpinonic acid, C10 hydroxy dicarbonyls, pinic acid, 2,2-dimethyl-3-(formylmethyl)-cyclobutane-formic acid, and a product that has a molecular weight of 156 and contains a C=O and a COOH/OH group. The latter two products have not been reported previously. Δ3- Carene is structurally analogous to α-pinene in that both have an internal unsaturated bond where ozone oxidation takes place. We have also identified the corresponding analogous products, of which all but caronaldehyde are reported for the first time. An analytical method was developed to identify compounds containing one or more functional groups of carbonyl, carboxyl and hydroxyl in atmospheric samples. -C-to-O double bond groups are derivatized using 0-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine, and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)-trifluoroacetamide. The derivatives are resolved using a gas chromatography column coupled with mass spectrometry. The method identified products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene.
