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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 57 for “"(E)-/(Z)-"”.
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The E/Z isomerization step in the biosynthesis of Z coniferyl alcohol in Fagus grandifolia Ehrh.
In nature, it has long been assumed that p-hydroxycinnamyl alcohols occur exclusively in their trans (E) stereoisomeric form. However, in beech bark (Fagus grandifolia Ehrh.) only the corresponding cis (Z) monomers were found. Experiments with beech bark and 2-¹⁴C-labelled E ferulic acid, E …
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Synthesis of Insecticidal Mono- and Diacylhydrazines for Disruption of K+ Voltage-Gated Channels, and Elucidation of Regiochemistry and Conformational Isomerism by NMR Spectroscopy and Computation
Based on the success of diacyl-tert-butylhydrazines RH-5849 and RH-1266 in controlling agricultural crop pests, we endeavored to synthesize our own diacylbenzyl- and arylhydrazine derivatives for use against the malaria vector Anopheles gambiae. In the process of producing a library of compounds …
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JULIA-KOCIENSKI APPROACH TO 4-SUBSTITUTED 1- ALKENYL-1H-1,2,3-TRIAZOLES
<p>A modular approach to the synthesis of 4-substituted N-vinyltriazoles was<br />developed. The triazole cores were assembled by copper-catalyzed 1,3-dipolar<br />cycloaddition of 1-phenyl-1H-tetrazol-5-yl (PT) azidomethyl sulfide with: pmethoxyphenyl, 2-pyridyl, and triisopropylsilyl alkynes. …
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Applications of nitroalkene (4+2); cycloaddition chemistry. The asymmetric synthesis of substituted pyrrolidines and the total synthesis of mesembrine
A general route for the preparation of 2,2-disubstituted 1-nitroalkenes has been developed. Conjugate 1,4-addition of zinc cuprates (RCu(CN)ZnI) to easily obtained (E)-1-nitroalkenes, followed by trapping with phenylselenenyl bromide, and subsequent oxidative elimination afforded the corresponding …
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Synthese von Carbo- und Heterocyclen durch Ruthenium-katalysierte Kreuzmetathese Beiträge zur Katalysatorentwicklung
Ruthenium-katalysierte Kreuzmetathesereaktionen sind C-C-Kupplungsreaktionen mit wachsendem Synthesepotential. Zielstrukturen können modular und flexibel aufgebaut werden, wobei eine Reihe von Funktionalitäten und Strukturmotiven toleriert werden. Das umsetzbare Substratspektrum ist durch die …
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Fluorescent ajoenes as a mechanistic probe for cancer
This thesis describes the development and synthesis of several novel ajoene mimics. The first of which, (E/Z)-1,8-(Bis-p-methoxyphenyl)-2,3,7-trithia-octa-4-ene 7-oxide 17, was developed as a continuation of SAR studies performed by our group, involved the placing p-methoxyphenly groups on the …
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Palladium-Catalyzed Cross -Coupling Reactions of Organosilanolates: Methods Development and Application in the Total Synthesis of (+)-Papulacandin D
Finally, an E,Z-1,4-bissilylbutadiene reagent was prepared for the synthesis of unsymmetrical, highly conjugated systems. Two distinct silyl substituents were differentiated in the cross-coupling reaction through the initial use of base-promoted reaction conditions where only one silyl group was …
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Blending synthetic pheromones of cerambycid beetles to develop trap lures that simultaneously attract multiple species
We evaluated attraction of cerambycid beetle species to blends of known cerambycid pheromones to determine whether such blends could be used as effective trap lures for detecting and monitoring multiple species simultaneously. Pheromone-baited traps captured 1,358 cerambycid beetles, of which 1,101 …
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Topics on the Spectral Theory of Automorphic Forms
We study the analytic properties of the Eisenstein Series of $frac {1}{2}$-integral weight associated with the Hecke congruence subgroup $Gamma_0(4)$. Using these properties we obtain asymptotics for sums of certain Dirichlet $L$-series. We also obtain a formula reducing the study of Selberg's …
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Neutral receptors for anion recognition: synthesis, selectivity studies and transport properties
This thesis reports the synthesis and studies of a new series of compounds containing urea groups that can function as selective anion receptors and efficient anion transmembrane transporters. Two new asymmetric ureidic receptors L1 (1-(1H-indol-7-yl)-3- (quinolin-2-yl)urea) and L2 …
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Le traitement lexical préliminaire est-il suffisant pour sauter un mot de fonction lors de la lecture de phrases ?
"Alors qu'il est entendu que le saut des mots en lecture peut être un événement délibéré et planifié, le débat quant à son interprétation fait, encore aujourd'hui, couler beaucoup d'encre. Plus précisément, le débat porte sur l'étendue de l'analyse lexicale des mots sautés. Tandis …
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The synthesis, characterisation and photochemistry of novel organometallic complexes
Complexation of an organic ligand by a transition metal can radically alter the ligand photochemistry. In order to investigate these effects, we synthesised a series of organometallic complexes with several different modes of ligand-metal bonding. The synthesis of various cyclopentadienyl, arene, …
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Entwicklung neuer chiraler Rutheniumkatalysatoren und deren Anwendung in der asymmetrischen Olefinmetathese
Im ersten Teil der vorliegenden Arbeit gelang es ausgehend von der Aminosäure L-Valin neun neue chirale NHC-Liganden zu synthetisieren. Diese weisen als neues Strukturmotiv eine C1 Symmetrie und eine Monosubstitution im Rückgrat des N-heterocyclischen Carbenliganden (NHC) auf. Die entwickelte hoch …
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Investigation of Genetic and Environmental-Associated Variation of Flavor-Related Attributes in Bioparental and Natural Cucumber Populations and Their Correlation with Human Sensory
Fresh cucumber sensory quality is composed of texture, taste (non-volatiles), and aroma (volatiles), yet little is known about genetic variation in natural populations and influence of internal and external factors on these traits. This study hypothesized that significant differences would be …
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Selective, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes
Catalytic addition reactions to alkynes are among the most useful and efficient methods for preparing diverse types of substituted olefins. Controlling both regioselectivity and (EIZ)- selectivity in such transformations presents a significant challenge. In reactions that also involve the creation …
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C6 and C9 volatile compounds in 223 cucumbers (cucumis sativus L.) In Genome-Wide Association Studies (GWAS)
Volatile profile analysis has been conducted on limited cucumber varieties. This research aimed to quantify C6 and C9 compounds in 223 GWAS cucumber varieties. A comprehensive analysis of volatiles was performed using solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). …
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Acyclic Imidate and Thiomidate Normal-Oxides: Nitrones of Esters and Thioesters (alpha-Alkoxynitrones, Alpha-Alkylthionitrones, Normal - Alkylthiohydroxamic Acids, X-Ray)
Two N,O-dialkylacetimidate N-oxides and their hydrochlorides, and the hydrochloride of O-ethyl-N-methylpropionimidate N-oxide were prepared in dichloromethane solutions by the acid-catalyzed condensation of N-alkylhydroxylamines with aliphatic orthoesters. The (alpha)-alkoxynitrones and their …
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Quantized multiplicative quiver varieties and actions of higher genus braid groups
In this thesis, a new class of algebras called quantized multiplicative quiver varieties A (Q), is constructed, depending upon a quiver Q, its dimension vector d, and a certain "moment map" parameter . The algebras Ad(Q) are obtained via quantum Hamiltonian reduction of another algebra D,(Matd(Q)) …
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The use of chiral auxiliaries in the synthesis of chemically and biologically important chiral compunds
Chiral synthons of chemical and biological importance have been synthesised using imidazolidinone and Evans' oxazolidinone chiral auxiliaries (CA). The thesis comprises two parts, which were carried out at the Universities of Cape Town, RSA and University of Michigan in the USA. In part 1, carried …
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