14246-15-2Relevant 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).
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.
PROTECTION OF ALCOHOLS AND ACIDS WITH ALLYLSILANES CATALYZED BY IODINE OR IODOTRIMETHYLSILANE IN CHLORINATED HYDROCARBON
Hosomi, Akira,Sakurai, Hideki
, p. 85 - 88 (2007/10/02)
Many triorganosilyl ethers and esters were prepared by the reaction of allylsilanes with alcohols catalyzed by iodine or iodotrimethylsilane in excellent yields.Bromine and bromotrimethylsilane were also effective catalysts.
DOUBLE BOND CLEAVAGE REACTION OF SILYL ENOL ETHERS USING MoO2(acac)2-tBuOOH
Kaneda, Kiyotomi,Kii, Nobuyoshi,Jitsukawa, Koichiro,Teranishi, Shiichiro
, p. 2595 - 2598 (2007/10/02)
The double bond of various silyl enol ethers is smoothly cleaved to give carbonyl compounds by an oxidizing reagent MoO2(acac)2-tBuOOH.
