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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

C.O. Rosenius som teolog. Grunddragen i hans åskådning.

Lindholm, Ture, January 1900 (has links)
Thesis--Lund. / Summary in German. Bibliography: p. 159-160.
2

Gröna kvarter : En fallstudie om ekosystemtjänster för kvartersupprustning i Björkhagen

Sellgren, Felicia January 2017 (has links)
No description available.
3

Estudos biol?gicos de Rhipicephalus sanguineus e intera??o Rickettsia rickettsii, R. sanguineus e c?es em condi??es laboratoriais. / Biological studies on Rhipicephalus sanguineus and interactions of Rickettsia rickettsii, R. sanguineus and dogs under laboratory conditions.

Piranda, Eliane Mattos 29 February 2008 (has links)
Made available in DSpace on 2016-04-28T20:16:26Z (GMT). No. of bitstreams: 1 2008- Eliana Mattos Piranda.pdf: 1406016 bytes, checksum: c9a77c6cc1de7bc1adde1a6eb06a7a84 (MD5) Previous issue date: 2008-02-29 / Funda??o de Amparo a Pesquisa do Estado de S?o Paulo / The bacterium Rickettsia rickettsii is the etiological agent of an acute, severe human disease called Rocky Mountain Spotted Fever in the United States or Brazilian Spotted Fever in Brazil. The infection occurs through the tick bite. Reports of clinical illness on dogs due to this agent have been restricted to the United States. The brown dog tick or kennel tick, Rhipicephalus sanguineus (Latreille, 1806) is the most widespread tick species throughout the tropics and subtropics. Biological studies on ticks are very important to the tick-borne pathogens transmission knowledge. For this purpose, the present study evaluated experimental infection of dogs with a Itaia?u (Mogi das Cruzes/ S?o Paulo, Brasil) strain of R. rickettsii and some biological aspects of Rhipicephalus sanguineus. Initially, dogs were infected with R. rickettsii its susceptibility and the role of R. sanguineus as a vector was verified. In the second part the viability of adults ticks (R. sanguineus) on three different temperatures were tested. Ticks were maintained under the controlled conditions of 18 ? 1◦C, 27 ? 1◦C e 32 ? 1◦C e 80 ? 5% (temperature ? humidity) for different times without feed. The dogs were susceptible to R. rickettsii infection. R. sanguineus was able to acquire the pathogen and to transmit R. rickettsii to guinea pigs. Based on the second part s results, R. sanguineus viability is affected by both, temperature and unfed time. / A bact?ria Rickettsia rickettsii ? o agente etiol?gico de uma doen?a aguda e severa em humanos denominada Rocky Mountain Spotted Fever nos Estados Unidos e Febre Maculosa Brasileira no Brasil. A infec??o se d? pela picada de carrapatos. Relatos da doen?a cl?nica nos c?es s?o restritos aos EUA. O carrapato marrom do c?o ou carrapato dos canis, Rhipicephalus sanguineus (Latreille, 1806), ? a esp?cie de carrapato mais freq?ente nos tr?picos e subtr?picos. Estudos da biologia de carrapatos s?o de grande import?ncia para o entendimento da transmiss?o de biogentes. O objetivo do presente trabalho ? avaliar experimentalmente a infec??o nos c?es com R. rickettsii cepa Itaia?u (Mogi das Cruzes/ S?o Paulo, Brasil) e aspectos da biologia de Rhipicephalus sanguineus. Na primeira etapa, c?es foram infectados com R. rickettsii e avaliou-se a susceptibilidade dos animais a infec??o e o comportamento de R. sanguineus como vetor. No segundo experimento, adultos de R. sanguineus tiveram a viabilidade de infestar novos hospedeiros analisada. Os carrapatos foram mantidos a18 ? 1◦C, 27 ? 1◦C e 32 ? 1◦C e 80 ? 5% UR por tr?s per?odos de jejum. Observou-se que os c?es s?o suscept?veis a infec??o por R. rickettsii cepa Itaia?u. Foi verificado que R. sanguineus se infectam com R. rickettsii e s?o capazes de transmitir o agente a cobaias. Baseado nos resultados do segundo experimento, concluem-se que R. sanguineus tem a viabilidade influenciada pela temperatura e tempo de jejum.
4

Efficient C-O and C-N bond forming cross-coupling reactions catalyzed by core-shell structured Cu/Cu2O nanowires

Elshewy, Ahmed M. 12 1900 (has links)
Oxygen and Nitrogen containing compounds are of utmost importance due to their interesting and diverse biological activities. The construction of the C-O and C–N bonds is of significance as it opens avenues for the introduction of ether and amine linkages in organic molecules. Despite significant advancements in this field, the construction of C-O and C–N bonds is still a major challenge for organic chemists, due to the involvement of harsh reaction conditions or the use of expensive catalysts or ligands in many cases. Thus, it is a challenge to develop alternative, milder, cheaper and more reproducible methodologies for the construction of these types of bonds. Herein, we introduce a new efficient ligand free catalytic system for C-O and C-N bond formation reactions.
5

Formation de liaisons C-C et C-N par catalyse au Cuivre, au Fer ou en absence de metal de transition / Formation of C-C and C-N bonds catalyzed by Copper, Iron or transition metal-free

Berges, Julien 15 December 2016 (has links)
Le sujet de cette thèse se situe dans le cadre général des arylations de nucléophiles catalysées par des complexes de métaux de transitions (Cu, Fe) ou réalisées en absence de ces derniers, dans des conditions compétitives et respectueuses de l’environnement. Ces réactions sont d’une importance majeure pour l’industrie chimique. Dans un premier chapitre est tout d’abord décrit un couplage inédit mettant en jeu un sel d’aryldiazonium et un nucléophile azoté (formation de liaison CAr-N). La méthode procède dans des conditions douces via un système catalytique au cuivre peu coûteux et peu toxique. Les produits de couplage obtenus (Ar-NHet) sont d’un intérêt central dans l’industrie pharmaceutique et agrochimique. Dans une deuxième partie nous avons présenté une méthode permettant de réaliser le couplage entre des sels d’aryldiazonium et des dérivés du styrène, à l’aide d’un système t BuOK/DMF. Cette réaction, réalisée pour la première fois en absence de catalyseurs à base de métaux de transition, permet d’accéder, via la formation de liaisons CArsp²-Csp², à des motifs stilbènes variés qui trouvent de nombreuses applications en chimie pharmaceutique. Un deuxième chapitre porte sur l’utilisation de dérivés de l’iode hypervalent permettant la fonctionnalisation de noyaux aromatiques (C-H) ou de dérivés vinyliques (C-H). Une première méthode décrit une réaction de triflimidation directe de composés acétanilides avec une sélectivité exclusive en position para. Deux conditions réactionnelles ont été mises en place pour cette fonctionnalisation. Une première utilise une quantité stœchiométrique de PhI(OAc)2 et une autre utilise une quantité catalytique d’iodotoluène (génération in-situ de l’iode(III)). Cette transformation a conduit à la formation de liaisons CAr-N en présence de bis(trifluorométhane)sulfonimide de lithium (LINTf2) comme nucléophile azoté. Dans une deuxième partie, nous avons montré que l’iodure de bisphosphoranilidène (PNPI), pouvait catalyser la trifluorométhylation vinylique sélective de dérivés du styrène en présence d’un réactif de l’iode hypervalent (l’iode(III)), le réactif de Togni II. Des travaux sont en cours pour tenter de comprendre l’influence positive de l’utilisation de PNPI dans le cas de notre réaction. Un troisième chapitre décrit des résultats préliminaires permettant d’obtenir un rendement honorable (54%) lors du couplage catalysé au fer du 4-iodotoluène avec le phényllithium. Une autre série de test décrit le couplage entre des halogénures d’aryle et des alkyllithium primaires. La méthode semble très efficace, puisque par ailleurs les travaux très récents de la littérature pour des couplages similaires faisant intervenir les mêmes partenaires réactionnels, font appel à des catalyseurs de fer ou de palladium. / This thesis is part of a very general search seek to develop methodologies for environmentally sustainable conversion of small molecules into more valuable substances catalyzed by copper and iron complexes or under metal-free conditions. The work focuses on the functionalization of aromatic rings by C-C or C-N bond formation.In a first chapter, a novel coupling involving an aryldiazonium salt and a nitrogenous nucleophile (CAr-N bond formation) is first described. The method proceeds under mild conditions using a cheap and non-toxic copper catalyst system. The obtained coupling products (Ar-NHet) are of central interest in the pharmaceutical and agrochemical industry. Then in a second part, a method allowing the coupling between aryldiazonium salts and styrene derivatives, using a BuOK / DMF system is presented. This reaction, carried out for the first time in the absence of catalysts based on transition metals, makes it possible to access to various stilbene units which find numerous applications in pharmaceutical chemistry.A second chapter concerns the use of hypervalent iodine derivatives allowing the functionalization of aromatic or vinyl substrates. A first method describes a direct triflimidation reaction of acetanilide compounds with an exclusive selectivity in the para position. Two reactions conditions have been established for this functionalization. One uses a stoichiometric amount of PhI(OAc)2 and another uses a catalytic amount of iodotoluene (in-situ generation of iodine (III)). This transformation resulted in the formation of CAr-N bonds in the presence of lithium bis (trifluoromethane) sulfonimide (LINTf2) as the nitrogen nucleophile. In a second part, we have shown that bisphosphoranilidene iodide (PNPI) can catalyze a selective vinylic trifluoromethylation of styrene derivatives in the presence of a hypervalent iodine reagent (iodine (III)), Togni’s reagent II. Work is under way to try to understand the positive influence of PNPI.A third chapter describes preliminary results of an iron-catalyzed heterocoupling of 4-iodotoluene an phenylithium system allowing the obtention of an honorable yield (54%) during the coupling of 4-iodotoluene with phenyllithium. Another series of tests describes the coupling between aryl halides and primary alkyllithiums. The method seems to be very effective, since very recent work in the literature for similar couplings involving the same reaction partners involves catalysts of iron or palladium.
6

Activation de liaisons C-O catalysée par le nickel et sulfénylation de liaisons C-H / Nickel-catalyzed C-O bond activation and sulfenylation of C-H bonds

Hostier, Thomas 02 December 2016 (has links)
La mise au point de nouvelles méthodes de synthèse flexibles, robustes et polyvalentes pour la formation régiosélective de liaisons carbone-carbone ou carbone-hétéroatome représente un défi perpétuel en chimie organique. Dans le cadre de nos travaux, nous avons développé des protocoles efficaces et faciles à mettre en œuvre portant sur l’activation de liaisons C-O catalysée par le nickel et la sulfénylation de liaisons C-H sans métal. Nous avons démontré que l’utilisation d’un système catalytique simple à base d’acétate de nickel(II) et d’oxyde de triphénylphosphine dans des conditions douces (40 °C) permettait de réaliser le couplage croisé entre un éther d’énol méthylique et un réactif de Grignard via l’insertion du Ni dans la liaison C OMe. Une réaction de sulfénylation électrophile de composés (hétéro)aromatiques a également été développée. L’emploi de N-thiosuccinimides comme partenaires soufrés, en présence d’acide trifluoroacétique, nous a permis de réaliser avec une très bonne régiosélectivité la sulfénylation d’aromatiques électro-enrichis. Cette méthode a également été appliquée à des indoles non protégés afin d’accéder à des 2-thioindoles fonctionnalisés. / The development of new flexible synthetic methods for the regioselective formation of carbon carbon or carbon-heteroatom represents an ongoing challenge in organic chemistry. The work presented in this manuscript concerns the development of efficient and easy to implement protocols on nickel-catalyzed C-O bond activation and metal-free C-H sulfenylation.It was demonstrated that the use of a single catalytic system based on nickel(II) acetate and triphenylphosphine oxide under mild conditions (40 ° C) could perform the cross-coupling between an alkenyl methyl ether and a Grignard reagent via the insertion of the Ni catalyst into the C-OMe bond. An electrophilic sulfenylation reaction of (hetero)aromatics has also been developed. The use of N thiosuccinimides as sulfenylating partners, in the presence of trifluoroacetic acid, allowed us to achieve with a very good regioselectivity the sulfenylation of electron-rich aromatics. This method was also applied to unprotected indoles in order to access functionalized 2 thioindoles.
7

Rhodium and Palladium Catalysed Domino Reactions of Alkenyl Pyridines and Alkenyl Pyrazines

Friedman, Adam Alexander 22 November 2013 (has links)
Domino catalysis is an ideal strategy in the synthesis of heterocyclic scaffolds, as multiple bonds can be formed under a single set of reaction conditions. In this work, we present the development of two novel domino processes which afford access to aza-analogues of the dihydrodibenzoxepine motif. Careful optimisation revealed that the Rh catalysed hydroarylation proceeds under mild conditions as compared to the C-O coupling. Furthermore, Pd was not required for the C-O bond formation when using alkenyl pyrazines as substrates. Variation of the substituents on both the heterocycle and on the boronic ester provided insight into the structural features required for successful domino reaction, and a stepwise protocol was developed for incompatible substrates. We have also developed the first multi-metal, multi-ligand domino reaction featuring both a chiral and achiral ligand in the same pot, still leading to an enantioenriched product.
8

Rhodium and Palladium Catalysed Domino Reactions of Alkenyl Pyridines and Alkenyl Pyrazines

Friedman, Adam Alexander 22 November 2013 (has links)
Domino catalysis is an ideal strategy in the synthesis of heterocyclic scaffolds, as multiple bonds can be formed under a single set of reaction conditions. In this work, we present the development of two novel domino processes which afford access to aza-analogues of the dihydrodibenzoxepine motif. Careful optimisation revealed that the Rh catalysed hydroarylation proceeds under mild conditions as compared to the C-O coupling. Furthermore, Pd was not required for the C-O bond formation when using alkenyl pyrazines as substrates. Variation of the substituents on both the heterocycle and on the boronic ester provided insight into the structural features required for successful domino reaction, and a stepwise protocol was developed for incompatible substrates. We have also developed the first multi-metal, multi-ligand domino reaction featuring both a chiral and achiral ligand in the same pot, still leading to an enantioenriched product.
9

HYDROGENATION AND HYDROGENOLYSIS OF FURAN DERIVATIVES USING BIPYRIDINE-BASED ELECTROPHILIC RUTHENIUM(II) CATALYSTS

Gowda, Anitha Shankaralinge 01 January 2013 (has links)
The catalytic activity of ruthenium(II) bis(diimine) complexes cis-[Ru(6,6′-Cl2bpy)2(OH2)2](Z)2 (2, Z = CF3SO3; 3, Z = (3,5-(CF3)2C6H3)4B ,i.e. BArF), cis-[Ru(4,4′-Cl2bpy)2(OH2)2](Z)2 (4, Z = CF3SO3; 5, Z = BArF) and cis-[Ru(bpy)2(PR3)(OH2)](CF3SO3)2 (7, bpy = 2,2’-bipyridine, PR3 = P(C6H4F)3; 8, bpy = 2,2-bipyridine, PR3 = PPh3; 9, bpy = 4,4’-dichloro-2,2’-bipyridine, PR3 = PPh3; 10, bpy = 4,4’-dimethyl-2,2’-bipyridine, PR3 = P(C6H4F)3) for the hydrogenation and hydrogenolysis of furfural (FFR), furfuryl alcohol (FFA) and 5-hydroxymethylfurfural (HMF) was investigated. The compounds 2-5 are active and highly selective catalysts for the hydrogenation of FFR to FFA. Using 2 as catalyst at 100 °C, hydrogenation of FFR proceeded to high conversion (≥98%) and with 100% selectivity to FFA in 2 h. The catalyst cis-[Ru(6,6′-Cl2bpy)2(OH2)2](CF3SO3)2 (2) also showed some activity for hydrogenolysis of FFR and FFA at 130 °C in ethanol, giving up to 25% of 2-methylfuran (MF) yield. The catalyst 3 alsodisplayed high catalytic activity for the hydrogenation of FFA to tetrahydrofurfuryl alcohol. Catalysts 7-10 are also active towards the hydrogenation of furfural (FFR) in NMP giving >90% FFR conversion with 100% selectivity for furfuryl alcohol (FFA) in 12 h. Compounds 7-10 are active C-O bond hydrogenolysis catalysts in presence of bismuth halide Lewis acids. For example, hydrogenolysis of FFA in the presence of 1 mol% of catalyst cis-[Ru(4,4’-Cl2bpy)2(PPh3)(OH2)](CF3SO3)2 (9) and 20 mol% bismuth bromide at 180 °C/51 atm H2 pressure gave >96% conversion of FFA and 55% MF yield. Compounds 7-10 in the presence of bismuth halides, showed almost 100% conversion of HMF with a very high selectivity (65-72%) for 2,5-DMF, along with 10-12% of MF, and trace amount of 5-methylfurfural (MeFFR). In order to test the activity of ruthenium hydrides towards the C-O bond hydrogenation and hydrogenolysis of HMF, series of monocationic ruthenium complexes cis-[Ru(bpy)2(PR3)(H)](CF3SO3) (12, bpy = 2,2’-bipyridine, PR3 = P(C6H4F)3; 13, bpy = 2,2-bipyridine, PR3= PPh3; 14, bpy = 4,4’-dimethyl-2,2’-bipyridine, PR3= P(C6H4F)3) were prepared. The hydrogenation of HMF using catalysts 12-14, produced 70-72% of 2,5-DMF and 11% MF, suggesting that ruthenium hydrides are active and efficient catalysts for HMF hydrogenation.
10

Sequential processes using catalytic C-O bond activation

Harkness, Gavin J. January 2018 (has links)
This thesis is centred around sequential C-C bond forming processes using oxygenated electrophiles. A major part of this research focuses on the constructive deoxygenation of 2-methoxyphenol (guaiacol), a major breakdown product of the renewable feedstock, lignin. 1,2-dielectrophiles are known to be challenging substrates for catalysis if both leaving groups are of similar reactivity, however high selectivity was observed in the palladium- catalysed Grignard cross-coupling of 2-methoxyphenyl-1H-imidazole-1-sulfonate. The previously untested Grignard cross-coupling catalyst, [PdCl₂(Xylyl-Phanephos)], was found to be highly active. A 2-benzoxazolyl functionality was shown to be an excellent directing group for the chelation-controlled nucleophilic aromatic substitution of aryl methyl ethers. However, this modified Meyers reaction is limited to aryl ethers containing an ortho-chelating group. To expand the ether scope, nickel-catalysed Grignard cross-coupling was studied. [NiCl₂(PⁿBu₃)2] showed increased activity in the Grignard cross-coupling of challenging ortho-substituted anisoles compared to the well-renowned [NiCl₂(PCy₃)2] and several Ni0 -NHC systems, with a ligand steric effect demonstrated. The success of [NiCl₂(PⁿBu₃)2] was extended to more activated methoxynaphthalene substrates, in which the lowest reported catalyst loadings (0.1-0.25 mol%) were reported. Induction periods at 0.1 mol% suggested the requirement of inorganic Lewis-acidic magnesium salts to be formed in situ before any considerable activity was observed. Further work is required to increase reaction and ether scope, but this work provides a basis for exploiting lignin- derived phenols as a framework in the synthesis of functionalised chemicals of higher value. The final results chapter concerns an alternative sequential C-C bond forming process using another oxygenated electrophile. [PdCl₂((S)-Xylyl-Phanephos)] was used to accomplish a Grignard cross-coupling of vinyl tosylate, with the product then subjected to a highly enantioselective methoxycarbonylation using the same catalyst. This lead to a concise synthesis of (S)-Flurbiprofen.

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