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Showing 1 to 20 of 66 for “"Diazo"”.
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Coupling reactions using flow-generated diazo compounds
… to access new sets of highly versatile, unstable diazo compounds and their application in coupling reactions. In the first chapter, an introduction into the structure and reactivity of diazo compounds is provided, as well as a discussion of currently available methods for their generation. The …
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Stabilisation of diazo compounds used in lithographic systems.
… to be due to the presence in the formulation of diazonium compounds that were thermally unstable. These compounds were studied in coating solutions and printing plates. Alternative analytical techniques for diazonium analysis were examined. It was found that HPLC and UV/vis spectroscopy were most …
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Development of imidazotetrazines for the treatment of glioblastoma & as synthetic precursors to diazo species
… such as TMZ are precursors to alkyl diazoniums, used therapeutically to alkylate DNA and elicit an anticancer effect. Given their stability as prodrugs and the reactivity of the species released, imidazotetrazines were repurposed into synthetic surrogates for diazomethane and other …
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Stereochemistry of the Allene-Forming Cycloelimination of 4-Diazo-3,5-Diethyl-3,5-Dimethyl-1-Pyrazoline
… stereochemical course of the decomposition of diazopyrazoline 1a to 3,5-dimethyl-3,4-heptadiene (2). To achieve this goal, a stereospecific synthesis of 1a which would permit its optical resolution was devised. Cyclization of tosylhydrazine and 4,5-epoxy-5-methyl-3-heptanone (3) provides a …
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Towards the development of a visible light-enabled histidine-selective protein modification strategy using diazo sulfonium-based probes
… strategy using visible light-activated -diazo sulfonium-based probes for the modification of histidine residues. Histidines represent attractive amino acid targets by virtue of their naturally low abundance but recurrent presence in protein active sites and pivotal biological roles. In …
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The Synthesis and Reactions of 2-Diazo-4,5-Bis(trifluoromethyl)imidazole, a Carbene Precursor to Stable Ylide and Hypervalent Compounds
The synthesis of 2-diazo-4,5-bis(trifluoromethyl)imidazole is discussed. An azo-linkage is used as a masked amine source in a fluorination reaction in which carboxylic acids are converted to trifluoromethyl groups. The azo compound is then hydrogenolyzed to the diazo compound precursor, …
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Photochemical transformations of α-diazocarbonyl compounds in flow
… aspects of the reactivity of a series of α-diazocarbonyl compounds including aryldiazoacetates, α-diazo-β-ketoesters and an α-diazo-β-ketosulfone, under continuous flow photolysis. These photochemical transformations yielded 2,3-dihydrobenzofurans, γ- and β-lactones, oxazoles and Wolff …
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Structure and Reactivity of Aryl Carbenes and Aryl Nitrenes: Experimental and Computational Approaches
… generated by photolyses of their corresponding diazo compounds. The physical and chemical behaviors of the diazo compounds and carbenes were examined and compared with their parent system, diazofluorene (DAF) and fluorenylidene (FL).
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Intramolecular carbenoid insertion : reactions of [alpha] -diazoketones derived from benzothienyl, pyrolyl and indolyl alkanoic acids with rhodium (II) acetate
… acetate decomposition chemistry observed for a-diazoketones tethered to thienyl, furanyl, and benzofuranyl moieties is dependent not only on the nature of the heteroatom but also on the length of the aliphatic tether linking the diazoketone moiety with the aromatic fragment. The present thesis …
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Preparation of the azo dyes; diazobenzene-acetoacet-alpha-naphthylamide; diazo-alpha-naphthylamine-acetoacetanilide and the isomeric meta- and para-nitro derivatives of diazobenzene-acetoacetanilide
… aceto-acetanilide. III. Dyes were prepared by diazotizing aniline and coupling with the para- and meta-nitro-aceto-acetanilide. To the present writing, our attempts to couple diazotized aniline with aceto-acet-alpha-naphthylamide have failed because of the extreme insoluble character of the …
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Investigation of catalyst effects in enantioselective copper- and rhodium-mediated transformations of α-diazocarbonyl compounds
… the synthesis and reactivity of a series of α-diazocarbonyl compounds with particular emphasis on the use of copper-bis(oxazoline)-mediated enantioselective C–H insertion reactions leading to enantioenriched cyclopentanone derivatives. Through the use of additives, the enantioselectivity …
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Novel synthetic methodology employing transition metal catalysed reactions of α-diazo-β-keto sulfonamides and α-cyano-α-diazoacetates; the impact of substituents on the reaction pathway
… focus of this thesis is the reactivity of α-diazo-β-keto sulfonamides, α-cyano-α-diazoacetates and α-arylsulfonyl-α-diazoacetates employing rhodium and copper catalysts. While the α-diazo-β-keto sulfonamides were specifically designed to investigate rhodium- and copper-catalysed …
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Synthetic and stereochemical aspects of enantioselective copper catalysed C-H insertion reactions leading to cyclopentanones and sultones
… thesis describes the synthesis of a series of α-diazocarbonyl compounds including α-diazoβ-keto sulfones, α-diazo-β-keto phosphine oxides, 2-diazo-1,3-diketones and αdiazosulfonates, and their reactivity in intramolecular copper–bis(oxazoline)–NaBARF catalysed C–H insertion reactions. Excellent …
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Applications of 2,3-Diketoesters in Organic Synthesis and Stereoselective Transformations
Dimethyldioxyrane oxidation of δ-hydroxy-α-diazo-β-ketoesters that are prepared by zinc triflate catalyzed Mukaiyama-aldol condensation of methyl diazoacetoacetates with aldehydes, occurred in quantitative yield to form dihydrofuranols that undergo acid catalyzed dehydration under mild conditions …
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Synthesis of highly substituted benzo-fused nitrogen heterocycles via tandem benzannulation/cyclization strategies
… and vinylketenes (generated in situ from [alpha]-diazo ketones) were investigated. Irradiation of the diazo ketones using a batch or continuous-flow reactor leads to the formation of vinylketenes via a photo-Wolff rearrangement. The vinylketenes then react with ynamides via a pericyclic cascade …
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Glycoprotein mimetic materials - synthetic methods and study of viral inhibition properties
… The first uses a combination of cysteine and diazo coupling reactions, while the second uses combination of global amino acid substitution and copper()-catalyzed alkyne-azide cycloaddition (CuAAC). The tyrosine enrichment required to prepare elastin-like-polypeptides (ELP) proteins for diazo …
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