Home About us Contact
|
Home About us Contact | ||
|
|
||
Mild Oxidation (mild + oxidation)
Selected AbstractsChemInform Abstract: Selective and Mild Oxidation of Thiols to Sulfonic Acids by Hydrogen Peroxide Catalyzed by Methyltrioxorhenium.CHEMINFORM, Issue 35 2008Francesco P. Ballistreri Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Efficient and Mild Oxidation of Sulfides to Sulfoxides by Iodosobenzene Catalyzed by Cr(salen) Complex.CHEMINFORM, Issue 10 2004Sung Soo Kim No abstract is available for this article. [source] Synthesis of the Clathrate-II K8.6(4)Ge136 by Oxidation of K4Ge9 in an Ionic LiquidEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2009Arnold M. Guloy Abstract The new clathrate-II K8.6(4)Ge136 has been synthesized by mild oxidation of K4Ge9 in the ionic liquid n -dodecyltrimethylammonium chloride (DTAC)/AlCl3 at 300 °C and subsequent annealing at 370 °C. Refinement of the crystal structure from X-ray powder diffraction data revealed the composition K8.6(4)Ge136 [space group Fdm, a = 15.302(1) Å], which was also confirmed by energy-dispersive X-ray spectrometry (EDXS), transmission electron microscopy, and scanning electron microscopy on the bulk material. K atoms preferably occupy the larger Ge28 cages rather than the Ge20 cages in the clathrate-II structure. K8.6(4)Ge136 is metastable and was found to decompose exothermically at 471 °C. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Interactions Between Wine Lees and Polyphenols: Influence on Oxygen Consumption Capacity During Simulation of Wine AgingJOURNAL OF FOOD SCIENCE, Issue 5 2002J.M. Salmon ABSTRACT: During wine aging on lees, some membrane lipids of yeast lees, in contact with dissolved oxygen at low concentration, may undergo mild oxidation explaining the capacity of yeast lees to consume oxygen. We studied the cross-reactivity of complex polyphenols and tannins from wine and yeast lees towards oxygen during simulation of wine aging. We observed a total decrease of oxygen consumption capacity of mixed yeast lees and wine polyphenol by comparison with the reactivity of each component studied alone. A strong loss of reactivity of yeast lees towards oxygen was observed when separated from soluble polyphenols, although only a fraction of the total polyphenols remained adsorbed on lees. [source] Mild oxidative cyclization of sydnone-benzoylhydrazone with lead oxide to 2,5-disubstituted-1,3,4-oxadiazole,sydnone hybrid derivativesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2009Kuo-Chen Chiang The mild oxidation of sydnone-benzoylhydrazone hybrids with lead oxide in acetic acid/dichloromethane solution inducted their intramolecular cyclization to provide the corresponding 2,5-disubstituted-1,3,4-oxidiazole derivatives. The sydnone moiety has been efficient preserved for the future work in the mild oxidation. J. Heterocyclic Chem., (2009). [source] A new amino acid derivative with a masked side-chain aldehyde and its use in peptide synthesis and chemoselective ligationJOURNAL OF PEPTIDE SCIENCE, Issue 10 2001Jane C. Spetzler Abstract A new amino acid derivative with a diol side-chain, ,,-2-amino-4,5-dihydroxy-pentanoic acid (Adi), has been prepared from ,,-allylglycine by suitable protection, for use in peptide synthesis, as Fmoc-,,-Adi(Trt)2. This building block enables the introduction of a side-chain aldehyde at any position in a given peptide sequence without use of specialized side-chain protection schemes. The aldehyde is revealed by mild oxidation with sodium periodate, circumventing the problematic release of reactive peptidic aldehydes in TFA solution. Peptides with aldehyde side-chains are useful for chemo-selective ligation, reacting selectively with oxyamines to yield oxime links, while all other peptide functions can be left unprotected. The utility of the new building block has been demonstrated by the synthesis of peptide dimers and a cyclo-peptide. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source] Evaluation of a hydrazide-linked ,1 -acid glycoprotein chiral stationary phase: Separation of R - and S -propranololJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2006Hai Xuan Abstract The binding and chiral separation of R - and S -propranolol was investigated on a new type of ,1 -acid glycoprotein (AGP) column. This column was prepared through the controlled and mild oxidation of AGP, followed by the immobilization of this protein to hydrazide-activated silica. The effects of temperature, pH, ionic strength, and organic modifiers on the retention and separation of R - and S -propranolol were investigated on this column. Both the association equilibrium constants and number of binding sites for R/S -propranolol on the AGP column were found to increase with temperature and affect the measured retention factors for these compounds. Regarding the other factors, a change in the organic modifier concentration was found to give the largest change in retention and separation. It was found through these studies that both coulombic and hydrophobic interactions played important roles in determining the retention of R - and S -propranolol on the AGP column. The efficiency and separation impedance of this system were also considered. Under the final optimum conditions identified in this study, it was possible to separate R - and S -propranolol with a resolution of greater than 1.38 in less than 5 min on a 4.1 mm I.D.×5 cm column. [source] | ||||||||||