Дисертації з теми "Catalytic cycles"
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Ceylan, Yavuz Selim. "Exploration of Transition Metal-Containing Catalytic Cycles via Computational Methods." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505287/.
Повний текст джерелаBhawal, Benjamin Niladri. "Discovery and development of catalytic syntheses of aza-cycles." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708586.
Повний текст джерелаShammas, Camille N. Y. A. "An investigation of the catalytic cycles of two dehydrogenases by X ray crystallography." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274756.
Повний текст джерелаStirling, Matthew John. "Coupled catalytic cycles : development of a procedure for the dynamic kinetic resolution of amines." Thesis, University of Huddersfield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438067.
Повний текст джерелаParker, Mariah L. "The Investigation of Oxidative Addition Reactions of Metal Complexes in Cross-Coupling Catalytic Cycles Based on a Unique Methodology of Coupled Ion/Ion-Ion/Molecule Reactions." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5651.
Повний текст джерелаSullivan, Ryan. "Improving Efficiency by Using Continuous Flow to Enable Cycles: Pseudo-Catalysis, Catalysis and Kinetics." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40387.
Повний текст джерела鄧文偉 and Man-wai Simon Tang. "Novel cyclic ketones for catalytic epoxidation of olefins." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31214654.
Повний текст джерелаTang, Man-wai Simon. "Novel cyclic ketones for catalytic epoxidation of olefins /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1853871X.
Повний текст джерелаRothnie, Alice. "TM6 of Pgp : changes in topography during the catalytic cycle." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401107.
Повний текст джерелаBelcastro, Elizabeth Lynn. "Life Cycle Analysis of a Ceramic Three-Way Catalytic Converter." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32342.
Повний текст джерелаMaster of Science
Miranda, Rojas Sebastián Esteban. "Theoretical insight into the catalytic cycle of cobalamin-glutamate mutase complex." Tesis, Universidad de Chile, 2012. http://repositorio.uchile.cl/handle/2250/105223.
Повний текст джерелаLas enzimas son capaces de acelerar reacciones químicas con una gran selectividad, permitiendo que la vida sea posible como la conocemos. Glutamato mutasa (GM) es una enzima dependiente de adenosilcobalamina (AdoCbl), la cual cataliza la isomerización reversible de glutamato (glm) a metilaspartato (masp). AdoCbl es un cofactor que consiste en un macrociclo ubicado en el plano ecuatorial denominado corrina, el cual tiene como átomo central un Co+3. Este metal está axialmente coordinado por un ligando desoxiadenosina e intramolecularmente por un grupo 5,6-dimetilbenzimidazol. El mecanismo propuesto para la reacción de isomerización comienza con la unión del sustrato al sitio catalítico, la cual induce la ruptura homolítica del enlace cobalto-carbono (Co-C) del cofactor. Como producto de esta disociación homolítica se forma el radical desoxiadenosilo (Ado•) que luego abstrae un hidrógeno desde el sustrato, formando un radical derivado del sustrato y AdoH. Este radical sufre un reordenamiento que da origen al radical relacionado con el producto, el cual reabstrae el hidrógeno desde AdoH, regenerando Ado•. El ciclo catalítico termina con la formación del enlace Co-C. La generación de intermediarios radicalarios altamente reactivos hace que esta reacción sea muy difícil de llevar a cabo sin reacciones secundarias. Es así que la necesidad de una maquinaria catalítica capaz de controlar los caminos de reacción sea indispensable. Una interesante pregunta en química bioinorgánica es cómo luego de la unión del sustrato, el complejo cofactor-enzima es capaz de modificar su estructura electrónica debilitando el enlace Co-C hasta su disociación homolítica. Además, el camino de reacción exacto que conecta el rompimiento del enlace Co-C con el proceso de abstracción del hidrógeno desde el sustrato permanece incierto. Finalmente, el papel exacto que cumple el entorno enzimático en el mecanismo de isomerización está lejos de ser completamente comprendido. La necesidad de una mayor comprensión del mecanismo catalítico de GM, especialmente el proceso de control de la ruptura del enlace Co-C y el mecanismo para controlar la transformación química catalizada por GM son interesantes problemas para ser resueltos por métodos químico computacionales. En este trabajo presentamos un conjunto de modelos químico-cuánticos obtenidos con el propósito de responder a las preguntar presentadas anteriormente. Primero, exploramos la naturaleza del enlace Co-C mediante en estudio comparativo de AdoCbl y un cofactor análogo conocido como MeCbl, ambos en sus formas libres. Segundo, obtuvimos un conjunto de modelos del cofactor unido a GM para explorar las fuerzas involucradas en el proceso de ruptura catalítica del enlace Co-C, junto con la influencia del sustrato en esta. Tercero, con el fin de comprender las fuerzas que manejan el ciclo catalítico, llevamos a cabo el estudio del estado fundamental, intermediarios clave y estados de transición del ciclo catalítico usando modelos del complejo GM-Ado-glm obtenidos a partir de cálculos de estructura electrónica. Los estudios de la disociación del enlace Co-C en complejo con la enzima y del ciclo catalítico fueron enfocados en el efecto del entorno enzimático cercano. La aproximación de cluster fue usando en todos los cálculos que involucraron a GM como parte del modelo. Nuestros principales resultados revelaron que el enlace Co-C es debilitado por el reemplazo de base axial que sufre luego de unirse a la enzima por el par histidina-aspartato. Además existe un efecto electrostático ejercido por el par lisina-glutamato de la enzima que estabiliza al radical Ado•. La presencia de glm tiene un papel importante luego de la formación del radical Ado• ya que permite la formación del radical un radical glm• que es más estable, propagando el ciclo catalítico hacia la formación del producto. Finalmente, nuestros hallazgos revelaron que el entorno enzimático conduce la reacción de isomerización mediante una estabilización diferencial de los intermediarios y estados de transición asociados a la reacción. Además provee de un importante soporte estructural. Los antecedentes entregados en este trabajo permitirán en el futuro el diseño de bio-miméticos capaces de catalizar reacciones químicas extremadamente complejas
Enzymes accelerate chemical reactions with exceptional selectivity making life itself possible. Glutamate Mutase (GM) is an adenosylcobalamin (AdoCbl)-dependent enzyme that catalyzes the reversible isomerization of glutamate (glm) to methylaspartate (masp). The AdoCbl cofactor consists of an equatorial corrin ring, which has a Co+3 as the metal center axially coordinated by a deoxyadenosyl moiety and intramolecularly by a 5,6-dimethylbenzimidazole group. The accepted mechanism for the isomerization reaction begins with substrate binding to the catalytic site, which induces the homolytic cleavage of the cobalt carbon bond (Co-C) of AdoCbl, being this the first catalytic event. This generates an adenosyl radical (Ado•) that subsequently abstracts a hydrogen atom from the substrate, forming a substrate-derived radical and AdoH. The newly formed radical rearranges to a product-related radical, which eventually re-abstracts the hydrogen from AdoH, leading into Ado• regeneration. Finally, the catalytic cycle ends by Co-C bond formation. The generation of highly reactive radical intermediaries makes this reaction very difficult to occur without side reactions. Thus, the need of proper catalytic machinery able to control the reaction pathway is mandatory. An intriguing question in bioinorganic chemistry is how upon substrate binding, the cofactorenzyme complex modifies its electronic structure weakening the Co-C bond strength until its homolytic dissociation. In addition, the exact reaction pathway that connects the Co-C bond breaking with the hydrogen abstraction from the substrate remains uncertain. Finally, the exact role of the enzymatic environment on the isomerization reaction mechanism is far from been completely understood. The need of deeper insights about the GM catalytic reaction, especially the control of the Co- C bond dissociation process and the mechanism to manage the chemical transformation are interesting challenges to be solved by computational chemistry approaches. Here we present a large set of quantum chemical models obtained to answer the questions above presented. First, we explored the nature of the Co-C bond by the comparative study of AdoCbl and an analogous cofactor known as methylcobalamin (MeCbl), both in their free forms. Second, a set of models of AdoCbl in complex with GM were obtained to explore the forces involved in the catalytic Co-C bond dissociation process and the influence of the substrate on it. Third, in order to shed light into the driving forces of the catalytic cycle, we performed the study of models of ground state, key intermediates and transition states of the catalytic cycle using GM-Ado-glm complexes by means of modern electronic structure calculations. In all the calculation involving the GM as part of the model, the cluster approach was used. The studies of the Co-C bond dissociation in complex with the enzyme and the study of the catalytic cycle were focused on the effect of the nearby enzymatic environment. Our main results revealed that the Co-C bond is weakened in part by the axial ligand replacement involving a histidine-aspartate pair, and the electrostatic effect exerted by the lysine-glutamate pair from the enzyme which stabilizes the Ado• radical. After the formation of the Ado•, the presence of glm leads to the formation of glm• radical, which is largely more stable than Ado•. Thus, glm has an important role on the propagation of the catalytic cycle toward the product formation. Finally, our findings revealed that the near enzymatic environment provides differential stabilization of the reaction intermediaries and transition state mediated by the properties of the interactions with the catalytic site. Additionally, it provides of an important structural support. This understanding would allow in the future the design of bio-mimetic able to catalyze highly complex reactions
Middleton, Ann Jenny. "Cyclic phosphines for hydroformylation catalysis." Thesis, University of Bristol, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412371.
Повний текст джерелаGriffin, Tim Robert. "Ab initio and density functional theory study of the Monsanto catalytic cycle." Thesis, University of Sheffield, 1997. http://etheses.whiterose.ac.uk/3445/.
Повний текст джерелаWilkinson, Craig. "Understanding the catalytic cycle of membrane pyrophosphatases through structural and functional studies." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/19131/.
Повний текст джерелаDaff, Simon N. "Analysis of the catalytic cycle & manipulation of substrate specificity in flavocytochrome b2." Thesis, University of Edinburgh, 1996. http://hdl.handle.net/1842/12172.
Повний текст джерелаNavarro-Fernandez, Oscar. "Synthesis, Activation and Catalytic Activity of N-Heterocyclic Carbene Bearing Palladium Catalysts." ScholarWorks@UNO, 2006. http://scholarworks.uno.edu/td/330.
Повний текст джерелаMartin, Catherine Anne. "P-glycoprotein transport cycle : 'cross-talk' between multiple binding sites and the catalytic domains." Thesis, Open University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369076.
Повний текст джерелаBowen, Laura Christine. "Cyclic AMP-dependent protein kinase catalytic subunit in the nematode 'Caenorhabditis elegans'." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402303.
Повний текст джерелаMohamad, Noh N. "Catalytic route for the synthesis of cyclic organic carbonates from renewable polyols." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3012167/.
Повний текст джерелаKong, Jianfeng. "Evidence for pH-dependent conformations in the catalytic cycle of cytochrome caa¦3 from B. subtilis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0004/MQ45281.pdf.
Повний текст джерелаYeamin, Md Bin. "Catalytic CO2 Cycloaddition with Epoxides into Cyclic Carbonates: Synergies from Computational to Experimental Studies." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672267.
Повний текст джерелаLa utilización del CO2 como materia prima química ha demostrado ser una estrategia importante para reducir las emisiones de CO2 a la atmósfera y, por tanto, para encontrar un equilibrio en el ciclo natural del carbono. Sin embargo, la activación de esta pequeña molécula estable es muy difícil. De hecho, los sustratos reactivos con alta energía interna pueden facilitar las transformaciones químicas del CO2 para compensar su estabilidad termodinámica. Además, se necesitan catalizadores eficaces para superar la elevada barrera cinética de la activación. Entre los muchos métodos catalíticos, la catálisis térmica sigue siendo el método más utilizado para ampliar los procesos de fijación de CO2 a nivel industrial. Se necesitan catalizadores con mayor actividad y selectividad en condiciones de reacción más suaves. Por lo tanto, nuestro objetivo es evaluar la eficiencia de los materiales de bajo coste y abundantes en tierra como catalizadores para la cicloadición de CO2 con epóxidos de alto contenido energético. También pretendemos entender el comportamiento de estos catalizadores a partir de estudios mecanísticos computacionales, y mejorar su diseño corroborando con su rendimiento catalítico experimental para esta reacción de transformación del CO2. En esta Tesis estudiamos tres catalizadores diferentes para la reacción de cicloadición de CO2 con epóxidos bajo gradiente térmico. Los catalizadores son biomasas lignocelulósicas como materiales vegetales más abundantes, 1,10-fenatronina derivada de cuatro donantes de nitrógeno que contienen complejos de zinc, y un complejo derivado de ciclam del elemento más abundante, el hierro. Los efectos cooperativos de estos catalizadores binarios en combinación con un cocatalizador, el bromuro de tetrabutilo y amonio (TBAB), se han dilucidado a partir de estudios mecanísticos computacionales. En los estudios experimentales, las reacciones catalíticas se optimizan para sustratos estándar, y los porcentajes de conversión de los sustratos se corroboran con las barreras de energía de activación de los mecanismos de reacción, cuando se aplican. También se analiza la naturaleza de los diferentes sitios activos catalíticos desde el punto de vista del alcance del sustrato.
CO2 utilization as a chemical feedstock has been proven as a major strategy to reduce CO2 emissions to the atmosphere, and therefore to find an equilibrium in the natural carbon cycle. However, activating this stable small molecule is very challenging. In fact, high internal energy-containing reactive substrates can facilitate chemical transformations of CO2 to compensate its thermodynamic stability. Moreover, efficient catalysts are needed to overcome the high kinetic barrier of activation. Among many catalytic methods, thermal catalysis is still the mostly used method to scale up the CO2 fixation processes at industrial level. Catalysts with higher activity and selectivity in milder reaction conditions are required. Therefore, we aim to assess the efficiency of low-cost earth-abundant materials as catalysts for CO2 cycloaddition with high energy-containing epoxides. We also aim to understand the behavior of these catalysts from computational mechanistic studies, and to improve on their design corroborating with their experimental catalytic performance for this CO2 transformation reaction. In this Thesis we study three different catalysts for CO2 cycloaddition reaction with epoxides under thermal gradient. The catalysts are lignocellulosic biomasses as most abundant plant materials, 1,10-phenathronine derived four nitrogen donor containing complexes of zinc, and a cyclam derived complex of the most abundant element iron. The cooperative effects of these binary catalysts in combination of a co-catalyst, tetrabutyl ammonium bromide (TBAB) are elucidated from computational mechanistic studies. In experimental studies, the catalytic reactions are optimized for standard substrates, and %substrate conversions are corroborated with the activation energy barriers from reaction mechanisms, where applies. Also, the nature of different catalytic active sites is analyzed from substrate scope standpoint.
Natarajan, Nallusamy. "Ligands build on macrocyclic platforms : can the macro cyclic unit influence the catalytic properties ?" Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF052.
Повний текст джерелаThis thesis describes the synthesis of a series of compounds built on conical resorcin[4]arene and calix[4]arene platforms: a) diphosphites derived from optically active binol, in which the phosphite moieties have been grafted to the wider rim of the generic cones. These ligands were assessed in asymmetric hydroformylation of vinyl arenes and led to high iso selectivity with good to excellent enantiomeric excess; b) N-heterocyclic carbenes bearing either one or two cavitand moieties and their use for the synthesis of [NiXCpL] complexes (X = Br or Cl, Cp = cyclopentadienyl, LH = NHC) in which the NiCp moiety has been supramolecularly trapped in a resorcinarene bowl. These complexes were found active in ethylene dimerization; c) bulky triazolium salts with one or two resorcinarene substituents that were found suitable for the synthesis of complexes with abnormal NHCs. The latter were tested in palladium-catalysed Suzuki-Miyaura cross-coupling of bulky aryl chlorides with sterically hindered aryl boronic acids. Better activities were observed with the sterically less hindered triazolium salt, which bears a single resorcinarene substituent. Its higher efficiency arises from a higher substrate accessibility in the resulting catalytic intermediates as well as the presence of flexible pentyl groups that may interact with the metal centre so as to facilitate the reductive elimination step
Wagner, Tristan. "Structural insights into mycobacterial central carbon metabolism : the catalytic mechanisms and regulatory properties of α-ketoglutarate decarboxylase (KGD)". Paris 6, 2011. http://www.theses.fr/2011PA066421.
Повний текст джерелаLaBarre, Michael James. "Investigation of the catalytic cycle of the molybdoenzyme sulfite oxidase: Synthesis and spectroscopic study of model systems." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/186051.
Повний текст джерелаMartorell, Colomer Aina. "Chiral biaryl monodentate cyclic phosphonites and phosphites for asymmetric catalysis." Thesis, University of Bristol, 2001. http://hdl.handle.net/1983/c3c79146-8c6a-4ba1-9eb6-6d5779456813.
Повний текст джерелаCastro, Pastrana Lucila Isabel. "Mycobacterial adenylyl cyclases Rv1625c and Rv0386 othodox vs. unorthodox catalysis /." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11051883.
Повний текст джерелаLawrence, Christopher Ralph. "Studies towards the catalysis of cationic cyclisations using monoclonal antibodies." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272265.
Повний текст джерелаSarkisian, Ryan Gregory. "MULTICOMPONENT REACTIONS OF SALICYLALDEHYDE, CYCLIC KETONES, AND ARYLAMINES THROUGH COOPERATIVE ENAMINE-METAL LEWIS ACID CATALYSIS." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1409236804.
Повний текст джерелаLiu, Kun. "Catalytic Asymmetric Synthesis of Chiral Cyclic Amines and Axially Chiral Anilides by Phase-Transfer Catalyzed Reactions." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/158098.
Повний текст джерелаCarberry, Brendan Patrick. "A theoretical and experimental investigation of the characteristics of automotive catalytic converters for use on two-stroke cycle engines." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310149.
Повний текст джерелаLiu, Rui. "Ruthenium (II) - catalysed enyne carbocyclization reactions." Thesis, Ecole centrale de Marseille, 2017. http://www.theses.fr/2017ECDM0004/document.
Повний текст джерелаThis dissertation focuses on cyclization reactions of 1,6-enynes involving ruthenium catalysts. Three different types of cyclization were developed from readily available precursors, such as 1,6-enynes and alkynes. In one application, a novel ruthenium-catalyzed hydroalkynylative cyclization of 1,6-enynes using terminal alkynes as co-reactants was explored. This reaction provides and entry to five-membered rings featuring an exocyclic 1,5-enyne motif. A neutral electron-rich ruthenium complex Cp*Ru(cod)Cl proved to be the catalyst of choice for these transformations. In another application, using the same complex, the ruthenium-catalyzed [2+2+2] cycloaddition of 1,6-enynes and alkynes was developed. Both internal and terminal alkynes were suitable substrates to access bicyclohexadienes with high yields in a single step. An intriguing ruthenium-catalyzed bicycloannulation of nitrogen-tethered 1,6-enynes has also been developed. For these cyclizations, only the electrophilic and alkynophilic ruthenium complex [RuCl2(CO)3]2 was able to perform the reaction. The exclusive formation of 3-azabicylo[4.1.0]hept-1-enes was observed with 1,6-enynes featuring an internal alkyne unit. These cyclization reactions fulfil the atom-economical reactions principle and are discussed on the basis of their mechanisms of formation
Pitaval, Anthony. "Gold catalysis for the synthesis of protoilludane sesquiterpenes and other cyclic systems." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/145765.
Повний текст джерелаLa catálisis homogénea con oro ha emergido como una poderosa herramienta en síntesis orgánica, dando a lugar muchosnuevosmétodospara la síntesis de productos naturales. En esta Tesis Doctoral, presentolaaplicación de la cicloisomerización de alquinos sustituidos con vinilciclopropanospara la síntesis de la repraesentina F. Como extensión de estas investigaciones, estudié la cicloisomerización de alenos con vinilciclopropanos con el objetivo de construir el esqueleto de varios sesquiterpenoides de la familia de los protoilludanos. Además de estos proyectos, he re-visitado la cicloisomerización de 1,6-eninos en la que no ocurre una 1,5-migración de grupos OR en posición propargílica. El mecanismo de la reacción se estudió por deuteración del alquino terminal, resultando ser un reordenamiento de tipo endopor ruptura simple.
Kumano, Takeshi. "Enantioselective Synthesis of Cyclic α-Amino Acids through Asymmetric Phase-Transfer Catalysis". 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/179375.
Повний текст джерелаWalter, Christopher John. "Stereoselective acceleration of Diels-Alder reactions by synthetic enzymes." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272679.
Повний текст джерелаNyadanu, Aude. "Nouvelles réactions multicomposants et ouverture de cycles contraints pour la synthèse d’hétérocycles." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX065/document.
Повний текст джерелаMulticomponent reactions (MCR) are a response to two big challenges faced by pharmaceutical chemistry : the discovery of new bioactive molecules and their production with reduced costs in a environmentally acceptable way. Indeed, by combining several reactants in one pot, MCR allow the synthesis of a wide diversity of complex molecules by simple and quick procedures, with good yields, and with limited amounts of reaction waste. In the framework of this thesis, we have developed new isocyanide-based multicomponent reactions, these compounds having an exceptionnaly rich reactivity.First, we were interested in the use of strong acids in the Ugi reaction. The first trials were made with sulfinic, sulfonic, phosphinic and phosphonic acids, and they failed. Nevertheless, thanks to the introduction of nitric acid as the acid component in the Ugi reaction, we described a one-pot synthesis of highly functionalized nitramines starting from an aldehyde, an isocyanide and an ammonium nitrate. This transformation is the first multicomponent reaction leading to a N-N bond formation.We also proposed a new variant for the Passerini reaction, involving thiocarbonyl derivatives. These compounds generally being quite unstable, we imagined a strategy in order to generate a thiocarbenium in situ from a 3-sulfanyl phthtalide, in the presence of titanium chloride. The coupling of this thiocarbenium with an isocyanide and a carboxylic acid leads to a divergent synthesis of two types of sulfur-containing heterocycles : thiophthalides and 3-amino-4-sulfanyl isocoumarines. This study represents the first formal approach of a Thio-Passerini reaction.Finally, as part of our continuing interest in in sulfur-containing derivatives, we described a new synthesis of thiovinylethers. These compounds, synthetically equivalent to thiocarbonyl derivatives, were obtained by the palladium-catalyzed ring opening of thiocyclopropanes.While the use of transition metals for constrained ring opening is well known for oxygen or nitrogen derivatives, this is the first reaction of this type for sulfur derivatives.Overall, we developed three original methodologies that give access to different types of functionalized compounds, potentially useful in pharmacy and agrochemistry. This work relies on the unique reactivity of isocyanides and adds on this especially rich chemistry
Karlsson, Erik. "Catalysts for Oxygen Production and Utilization : Closing the Oxygen Cycle: From Biomimetic Oxidation to Artificial Photosynthesis." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-56917.
Повний текст джерелаAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Accepted. Paper 6: Submitted.
Grogan, Gideon James. "Microbial biotransformations : oxygenation of cyclic ketones by Baeyer-Villiger monooxygenases from camphor-grown Pseudomonas putida NCIMB 10007." Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261493.
Повний текст джерелаSpielmann, Kim. "Synthèse asymétrique de petits cycles et leur réarrangement via des extensions cycliques." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2018. http://www.theses.fr/2018ENCM0015.
Повний текст джерелаThis manuscript deals with the asymmetrical synthesis of small cyclic compounds and their functionalization. In a first part, the enantioselective synthesis of α,β-unsaturated δ-lactones by a catalytic asymmetric vinylogous Mukaiyama reaction was examined. A multidisciplinary study made possible the elucidation of the whole catalytic cycle. Moreover, thanks to a stereospecific hydrogenolysis of these lactones, the total synthesis of two natural products, (R)-ar-Himachalene and (R)-curcumene, could be achieved.In a second part, a palladocatalyzed (3+2) cycloaddition reaction of vinyl aziridines and cyclopropanes was developed. Thus, highly functionalized imidazolidines and pyrrolidines could be isolated with good yields. Depending on the substrate used, different reaction behaviors could be highlighted. These small cycles can be considered as versatile "building blocks" to access more complex molecules
Guan, Shaoliang. "Determination of the role of nanoparticle active sites in catalytic hydrogenation reactions by cyclic voltammetry and novel in-situ surface spectroscopy." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/73388/.
Повний текст джерелаChung, Yongseong. "Diene substituent effects on the retro-Diels-Alder reaction and a formal catalytic cycle for ester hydrolysis based on the Michael/retro-Michael reaction /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487668215805488.
Повний текст джерелаCastro, Pastrana Lucila Isabel. "Mycobacterial adenylyl cyclases Rv1625c and Rv0386 orthodox vs. unorthodox catalysis = Die mycobakteriellen Adenylatcyclasen Rv1625c und Rv0386 /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=970608837.
Повний текст джерелаCarvalho, Rocha Catarina. "Towards a catalytic system allowing the "one-pot" conversion of alkenes into cyclic carbonates in the presence of dioxygen/carbon dioxide mixtures." Paris 6, 2013. http://www.theses.fr/2013PA066758.
Повний текст джерелаCes travaux visent à mettre au point un catalyseur hétérogène permettant la transformation directe d’un alcène en son carbonate cyclique en présence d’O2 et de CO2. Un complexe salen du MnIII et des sels d’ammonium quaternaires (SAQ) porteurs de groupements -(CH2)2OH ont été considérés comme phases actives pour les réactions d’époxydation et de cyclocarbonatation des époxydes, respectivement. L’activité de nombreux SAQ a été mesurée afin d’étudier l’influence de la structure de l’ammonium ainsi que des contre-ions. Le sel C16H33N(CH3)2(CH2CH2OH)+Br- (HEA16Br) est plus actif que la choline (HEA1Cl). Les calculs DFT ont permis d’étayer l’influence du groupement -(CH2)2OH ainsi que la réactivité particulière de l’ion HCO3-. Des matériaux siliciques de type SBA-15 porteurs de groupements CxHyN(CH3)2(CH2CH2OH)+ ont été obtenus : i) par imprégnation de Al-SBA-15 par HEA16Cl, ii) par ancrage covalent de groupements -C3H6N(CH3)2(CH2CH2OH)+Cl- (HEA3Cl) sur SBA-15. Dans les deux cas, les rendements en carbonate cyclique sont supérieurs à ceux obtenus en solution, a priori en raison d’un effet de synergie lié à la présence de silanols. Le complexe de MnIII ancré sur silice par le biais de ligands : i) dihydroimidazole, ii) phosphonate a donné des activités équivalentes à celle mesurée en solution mais avec un fort taux de lessivage de la phase active. Enfin, les premières études « one-pot » impliquant simultanément le salen du MnIII et HEA1Cl avec un mélange O2/CO2 ont été réalisées en faisant varier la température de 80 à 120°C en cours de réaction. Dans ces conditions, il apparait que l’aldéhyde sacrificiel non consommé lors de l’étape d’époxydation induit des réactions secondaires
Cook, Terry Ann. "Function and regulation of the delta subunit of PDE6 /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/6287.
Повний текст джерелаBailey, Gwendolyn Anne. "Inside the Cycle: Understanding and Overcoming Decomposition of Key Intermediates in Olefin Metathesis." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37501.
Повний текст джерелаElbert, Bryony L. "The synthesis and applications of cyclic alkenylsiloxanes." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:a332365e-22f2-4449-b517-3fd8a62ea8a3.
Повний текст джерелаChen, Li. "New developments in green asymmetric catalysis : Application to Michael reaction and ring opening polymerisation." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS162.
Повний текст джерелаOrganocatalyzed asymmetric synthesis is a growing and rapidly expanding research field for a greener chemistry. In this respect, we were interested in developing an organocatalyzed asymmetric Michael reaction taking advantage of H-bond catalysis and enamine activation allowing control of quaternary carbon center from unactivated ketones. Hence compared with well-known H-bond donor urea and thiourea organocatalysts, we first propose bifunctional squaramide organocatalysts for the one-pot transformation of unsymmetrical ketones to produce Michael adducts exhibiting a stereocontrolled quaternary carbon center in a neat microwave process. We also developped new catalytic systems based on the squaramide motive that are efficient and operationnaly simple, and produce Michael adducts in a good regioselectivity with an excellent enantio-selectivity. We also studied the usefulness of our systems in other transformations like green polymerization. In order to reduce the use of toxic metals to produce metal-free and well-defined polymers of environmental and medical significance, we also studied how our squaramide organocatalysts could control the green ring opening polymerization (ROP.The squaramide organocatalyst-based systems were also applicable to ROP to give polylactides of narrow dispersity and controlled molecular masses
Pankhurst, James Richard. "Complexes of Schiff-base macrocycles and donor-expanded dipyrrins for catalysis and uranyl reduction." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/28887.
Повний текст джерелаPaschkewitz, Timothy Michael. "Ammonia Production at Ambient Temperature and Pressure: An Electrochemical and Biological Approach." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/4893.
Повний текст джерелаGriffiths, Owen Glyn. "Environmental life cycle assessment of engineered nanomaterials in carbon capture and utilisation processes." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.629663.
Повний текст джерелаZhu, Jie. "Metal-cyclam based Metal-Organic Frameworks for CO₂ Chemical Transformations." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/86838.
Повний текст джерелаPh. D.