6787-10-6Relevant academic research and scientific papers
SILYLATED POLYALCOHOLS AND COMPOSITIONS THEREOF
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Page/Page column 29, (2018/09/26)
The present invention provides silylated polyalcohols, composition thereof and their use medical, insecticidal, prophylactic or therapeutic substances for the treatment or prevention of infection or infestation by arthropods. More specifically, the invention relates to the use of silylated polyalcohols and compositions thereof for treatment of lice infections.
Efficient room-temperature O-silylation of alcohols using a SBA-15-supported cobalt(II) nanocatalyst
Rajabi, Fatemeh,Luque, Rafael,Serrano-Ruiz, Juan Carlos
, p. 1823 - 1828 (2012/10/29)
The O-silylation of OH groups of alcohols and phenols with hexamethyldisilazane (HMDS) was achieved in high-to-excellent yields using catalytic quantities of a SBA-15-supported cobalt(II) nanocatalyst (typically 0.5 mol-%) at room temperature and under solvent-free conditions. Furthermore, the heterogeneous catalyst showed an excellent durability and can be conveniently reused by filtration for at least twelve times without any noticeable loss of activity. Copyright
Sulfated zirconia: An efficient catalyst for solvent-free synthesis of silyl ethers under mild conditions
Thirupathi, Boningari,Prasad, Avvari N.,Srinivas, Rapelli,Reddy, Benjaram M.
experimental part, p. 2064 - 2072 (2011/07/30)
Oximes, allylic, aliphatic, aromatic, cyclic, acyclic, and hetero alcohols are silylated in short reaction times with good yields in the midst of a catalytic amount of sulfated zirconia solid acid catalyst and trimethylsilyl cyanide under nonbasic, solvent-free, and ambient temperature conditions. Selectivity toward O-silyl ether rather than N-silyl ether has been observed. This simple experimental procedure, combined with easy recovery and reusability of the catalyst, is expected to contribute to the development of a clean and environmentally friendly strategy for the synthesis of O-silyl ethers. Copyright
A derivatization procedure for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates by GC-MS in mulberry (Morus sp.)
Rodríguez-Sánchez,Hernández-Hernández,Ruiz-Matute,Sanz
experimental part, p. 353 - 359 (2011/09/12)
Different derivatization procedures were assayed to simultaneously analyse iminosugars such as deoxynojirimycin (DNJ) or fagomine and other carbohydrates of low molecular weight by gas chromatography coupled to mass spectrometry (GC-MS) in Morus sp. Both oximation + trimethylsilylation and oximation + acetylation allowed the separation of target compounds, whereas trimethylsilyl (TMS) and acetylated derivatives showed several coelutions. Nevertheless, oximation + acetylation were discarded for giving inaccurate results for ketoses due to their incomplete derivatization. Different conditions for the conversion into trimethylsilyl oximes (TMSO) were assayed, the best results being achieved using hexamethyldisilazane with trifluoroacetic acid as silylation agent. Contents of iminosugars (DNJ, fagomine and pipecolic acid derivatives) and other carbohydrates such as mono and disaccharides, myo-inositol and galactinol isomers in mulberry extracts (fruits, leaves and branches) were determined by GC-MS using the TMSO procedure.
New approach to the synthesis of phosphorodichloridites, phosphorochloridites, and trialkyl phosphites
Majewski, Piotr
experimental part, p. 942 - 955 (2010/01/17)
Different trivalent organophosphorus esters such as phosphorodichloridites, phosphorochloridites, and mixed trialkyl phosphites have been easily synthesized in good yields using a HCl-catalyzed reaction of the corresponding chlorophosphine and alkoxytrimethylsilane by mutual exchange of the alkoxy and chlorine ligand pIIICl/ROSiR′3; exchange reaction). Chemoselectivity of the exchange reaction with primary and secondary alkoxytrimethylsilanes, as well as with alkoxytrimethylsilanes and thioalkoxytrimethylsilanes, respectively, has also been examined. It has been also found that the substitution reaction of chlorophosphines with secondary amine occurs more rapidly than the exchange reaction with ROSiR′ 3.
Time-dependent profiling of metabolites from Snf1 mutant and wild type yeast cells
Humston, Elizabeth M.,Dombek, Kenneth M.,Hoggard, Jamin C.,Young, Elton T.,Synovec, Robert E.
experimental part, p. 8002 - 8011 (2009/04/06)
The effect of sampling time in the context of growth conditions on a dynamic metabolic system was investigated in order to assess to what extent a single sampling time may be sufficient for general application, as well as to determine if useful kinetic information could be obtained. A wild type yeast strain (W) was compared to a snf1Δ mutant yeast strain (S) grown in high-glucose medium (R) and in low-glucose medium containing ethanol (DR). Under these growth conditions, different metabolic pathways for utilizing the different carbon sources are expected to be active. Thus, changes in metabolite levels relating to the carbon source in the growth medium were anticipated. Furthermore, the Snf1 protein kinase complex is required to adapt cellular metabolism from fermentative R conditions to oxidative DR conditions. So, differences in intracellular metabolite levels between the W and S yeast strains were also anticipated. Cell extracts were collected at four time points (0.5, 2, 4, 6 h) after shifting half of the cells from R to DR conditions, resulting in 16 sample classes (WR, WDR, SR, SDR) x (0.5, 2, 4, 6 h). The experimental design provided time course data, so temporal dependencies could be monitored in addition to carbon source and strain dependencies. Comprehensive two-dimensional (2D) gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS) was used with discovery-based data mining algorithms (Anal. Chem. 2006, 78, 5068-5075 (ref 1); J. Chromatogr., A 2008, 1186, 401-411 (ref 2)) to locate regions within the 2D chromatograms (i.e., metabolites) that provided chemical selectivity between the 16 sample classes. These regions were mathematically resolved using parallel factor analysis to positively identify the metabolites and to acquire quantitative results. With these tools, 51 unique metabolites were identified and quantified. Various time course patterns emerged from these data, and principal component analysis (PCA) was utilized as a comparison tool to determine the sources of variance between these 51 metabolites. The effect of sampling time was investigated with separate PCA analyses using various subsets of the data. PCA utilizing all of the time course data, averaged time course data, and each individual time point data set independently were performed to discern the differences. For the yeast strains examined in the current study, data collection at either 4 or 6 h provided information comparable to averaged time course data, albeit with a few metabolites missing using a single sampling time point.
Organocatalytic kinetic resolution of racemic primary alcohols using a chiral 1,2-diamine derived from (S)-proline
Terakado, Dai,Koutaka, Hitomi,Oriyama, Takeshi
, p. 1157 - 1165 (2007/10/03)
A highly efficient and good enantioselective organocatalytic asymmetric acylation of racemic primary alcohols with acyl chlorides has been achieved catalyzed by a chiral 1,2-diamine derived from (S)-proline.
Capillary gas-chromatographic analysis of monosaccharides: Improvements and comparisons using trifluoroacetylation and trimethylsilylation of sugar O-benzyl- and O-methyl-oximes
Andrews, Mark A.
, p. 1 - 19 (2007/10/02)
Two new procedures for the gas-chromatographic analysis of monosaccharides are reported. One involves derivatization of the sugars by reaction with O-benzylhydroxylamine followed by trifluoroacetylation with N-methylbis(trifluoroacetamide) and chromatography on a DB-1701 capillary column. This technique probably provides the best resolution achieved to date of the C3-C6 aldoses, as well as of the corresponding alditols. Ketoses can be qualitatively analyzed by this method, but complications interfere with their quantitative analysis. The second procedure also involves initial derivatization as the O-benzyloxime, but is followed by trimethylsilylation with 1-trimethylsilylimidazole, and chromatography on a DB-17 column. This technique is particularly useful for C5 sugars, C6 ketoses, and mixtures of sugars, alditols, and/or lactones. A number of additional, critical, observations on the derivatization and capillary gas-chromatographic analysis of monosaccharides are described.
