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Showing 1 to 19 of 19 for “"Diazomethane"”.
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Trimethylation Enhancement using Diazomethane (TrEnDi) Enhances Mass Spectrometry-Based Analysis of Glufosinate and 3-(Methylphosphinico)propionic Acid in Complex Matrices
… strategy trimethylation enhancement using diazomethane (TrEnDi), glufosinate and 3-MPPA react with diazomethane and tetrafluoroboric acid to become permethylated, thus reducing their polarity and forming a fixed permanent positive charge on the amine group of glufosinate. When using …
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Reactivity of a Low Valent Gallium Compound
… NacNacGa was treated with trimethylsilyl(diazomethane). Instead, a monomeric gallium nitrilimine and a metalated diazomethane were obtained. The gallium nitrilimine undergoes 1,3-addition reaction with phenylsilane and catecholborane forming gallium hydrazonides. Its reaction with diborane …
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Studies in Asymmetric Catalysis. Part I. Lewis Base-Catalyzed Aldol Additions. Part II. Bis(oxazoline)palladium(ii)-Catalyzed Cyclopropanation
… the cyclopropanation of ethyl (E)-cinnamate with diazomethane. Although an enantioselective process was never realized, effects of substitution on the ligand, catalyst loading studies, and other investigations led to a mechanistic proposal wherein partial or complete ligand dissociation occurs …
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Molekulare Dissoziation im elektronischen Grundzustand induziert durch Femtosekundenpulse im mittleren Infrarot
… scheme was demonstrated with metal carbonyls and diazomethane. Only ultrashort laser pulses allow for excitation and subsequent reaction on a time scale faster than the statistical energy redistribution (IVR).
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Methyl esterification of fatty acids and eicosanoids with a novel reagent trimethylsilyldiazomethane for analysis by gas chromatography-mass spectrometry
… and allergies. The reagent trimethyl silyl diazomethane (TMSD) which is less toxic and explosive than other reagents such as diazomethane, has been developed for use in the methyl esterification of drugs such as penicillin and some fatty acids. The objectives of the research were to (1) …
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A comparison of derivatisation procedures for the detection of multiple analytes in systematic forensic toxicology
… and a novel methylating agent trimethylsilyldiazomethane (TMS-diazomethane), used as a chromatographic derivatisation reagent for the first time in this study, and (c) silylation with tertiary-butyldimethylsilyl-trifluoroacetamide (MTBSTFA). Model compounds were selected for the evaluation …
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Effect of Phosphine Ligand Substitution on the Structures, Reactivities, and Ligand Rearrangements in Organotriosmium Compounds
… (mu-H)2Os3(CO)9L catalyze the polymerization of diazomethane. The nature of L has a strong effect on the rate of the polymerization. The rate constants for the compounds are as follows: L = CO 1.3 (2) min-1, PPh3 0.81 (12) min -1, P(p-MeOPh)3 58 (5) min-1, P(p-Tol)3 70 (6) min-1, PEt 3 0.23 (4) …
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NMR STRUCTURAL INVESTIGATIONS OF AQUATIC HUMIC SUBSTANCES (PYRAZOLINE, 1,3-DIPOLAR ADDITION, NITROGEN-15).
… procedure entailed methylation with ¹³C-diazomethane followed by permethylation with ¹³C-methyl iodide/sodium hydride, DMF the solvent in both steps. The ¹³C NMR of diazomethylated samples allows one to distinguish between carboxylic acid OH, phenolic OH, and phenolic OH adjacent to two …
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Development of imidazotetrazines for the treatment of glioblastoma & as synthetic precursors to diazo species
… were repurposed into synthetic surrogates for diazomethane and other diazoalkanes. TMZ was employed to conduct esterifications and metal-catalyzed cyclopropanations, with methyl ester formation from a wide variety of substrates proving efficient and operationally simple. As a commercially …
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[4 + 1] annulation reactions of (trialkylsilyl)ketenes : synthesis of substituted indanones and cyclopentenones
… reaction of TAS-arylketenes with trimethylsilyl diazomethane, has been developed. In addition, a new class of carbenoid reagents for our previously reported [4 + 1] cyclopentenone annulation has been identified. Studies have shown that the reaction of a- benzotriazolyl organolithium compounds …
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Gas chromatographic-electron capture analysis of disinfection byproducts from the chlorination of swimming pools and lake water
… that the methylation performed well however, the diazomethane methylated many compounds that were not being studied which interfered with the compounds that were being studied; The final portion of this research dealt with the levels of trihalomethanes produced by the chlorination of swimming …
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Enantioselective synthesis using bromoacetals.
… aryl esters followed by treatment with diazomethane afforded the corresponding methyl (S)-bromoalkyl esters with minimal racemisation, while treatment of these (S)-bromoalkyl aryl esters with an amine gave the corresponding amide with minimal racemisation. Reduction with sodium …
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Isolation and characterization of cathepsin Z, a lysosomal cysteine proteinase
… in human cultured cell lines using the peptidyl diazomethane inhibitor Fmoc-Leu-Leu- [¹²⁵]Tyr-CHN₂. The labeling of cathepsin Z by the inhibitor was both time- and concentration-dependent, and the proteinase was found in all human cell lines examined. The characteristics of cathepsin Z were …
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The synthesis, characterization, and use of a protein-cysteine proteinase inhibitor complex for the study of endosome/lysosome fusion
… internalized compounds, the deblocked peptidyl diazomethane inhibitor NH₂-Tyr-Ala-CHN₂ was cross-linked to bovine serum albumin (BSA) using the heterobifunctional crosslinking agent sulfo-SANPAH. This non-reducible cross-linked complex was used to characterize the inhibitory properties of the …
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Identification of pyruvate decarboxylase/indole pyruvate decarboxylase gene family members from Arabidopsis thaliana.
… as an internal standard, methylation with diazomethane, and GC-MS detection. Together, these methods provide important sensitive and precise methods for the search for IPDC activity in the plant kingdom.
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Studies on Syntheses of 1-Azaspirocycles, 2,6-Disubstituted 3-Piperidinols and cls-Decahydroquinolines
… and the amount of lithio(trimethylsilyl)diazomethane employed. Under the optimized reaction conditions, 7-methyl-2-azaspiro[4,4]non-6-ene-3-ones and 2-methyl-6-azaspiro[4,5]dec-1-ene-7-ones were obtained in very good yields. The application of the developed method was successfully …
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Quality and safety of oils and fats obtained as co-products or by-products of the food chain and destined to animal production
… assessed. Lipids were extracted, methylated with diazomethane, then transmethylated with 2N KOH/methanol and analyzed by GC and silver-ion TLC-GC. TFA and CLA were determined in the fats, the feedings, meat and liver of both poultry and rabbit. In general, the level of TFA and CLA in meat and …
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The Chemical Synthesis of Model Catalysts Related to Enzymes
… group to an acid chloride and treatment with diazomethane followed by hydrogen chloride. As a pilot synthesis, the chloromethyIketone was caused to react with N-benzylphenylacetamidine to produce N<sup>α</sup>-carbobenzoxy-1,2-dibenzylhistidine, which was purified by countercurrent …