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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.
151

Synthèse d’un inhibiteur de la rénine, l’aliskiren et développement de méthodes catalytiques d’alkylation asymétrique

Chénard, Étienne 05 1900 (has links)
Une nouvelle approche pour la synthèse de l’aliskiren, un puissant inhibiteur de la rénine pour le traitement de l’hypertension chez l’homme, a été développée. De cette approche, des étapes clés tels qu’une allylation avec un des catalyseurs de MacMillan, une cyclisation par métathèse (RCM) pour la préparation d’une lactone à neuf membres et une séquence de réactions d’aziridination diastéréosélective/réarrangement de cycle par une catalyse acide donnant un produit aminohydroxylé ont permis de compléter la synthèse de l’aliskiren en 11 étapes. Durant l’élaboration de la séquence de réactions pour la préparation de l’aliksiren, il a été noté que la lactone à neuf membres avait une facilité à se réarranger via des intermédiaires quinonoïdaux et les produits issus de cette tendance ont été analysés. De plus, une étude sur la réaction de RCM, donnant la lactone à neuf membres, a montré une dépendance envers la nature diastéréomérique du substrat de départ. Une méthodologie d’alpha-allylation asymétrique de cétones catalysée au palladium, tirant avantage d’un ligand chiral PHOX, a été explorée et utilisée en vue de la synthèse de l’aliskiren. De cette méthode, une étude pour la synthèse de produits alpha-allylcétones acycliques a été démontrée et un effet d’additif sur la sélectivité et la vitesse de réaction a été découvert. De plus, la production d’un intermédiaire avancé d’un produit d’intérêts a été accomplie et la nature de la contribution de l’additif a été investiguée. Les produits obtenus depuis la méthodologie d’allylation catalysée au palladium et la formation d’intermédiaire cationique des certains dérivés de la synthèse de l’aliskiren ont inspirés une nouvelle approche faisant appel à des techniques d’alkylation en catalyse acide pour la formation de produits diaryliques. Il a été trouvé que le catalyseur de chlorure d’or(III) et de triflate de bismuth(III) étaient particulièrement efficaces, démontrant une différence de cinétique pour la réactivité d’un mélange diastéréoisomériques d’alcools alpha-substitués de départ. / A new synthetic route toward aliskiren, a potent renin inhibitor for the treatment of hypertension in man, was achieved. In this approach, the use of key steps such as an asymmetric allylation catalyzed by one of MacMillan’s catalysts, a ring closing metathesis for the formation of a 9-membered lactone and a catalytic aziridination/diastereoselective acid-catalyzed ring rearrangement reaction sequence leading to an aminohydroxylated product permitted us to achieve an 11-step synthesis of aliskiren. While elaborating the sequence towards the inhibitor, the tendency of the cyclic intermediate to rearrange through a quinonoid intermediate was observed. The products of the rearrangement were analyzed. Furthermore, studies exploring the formation of the nine-membered ring lactone demonstrated a dependency on the diastereomeric nature of the substrates. A new allylation methodology was explored for the preparation of aliskiren, in which a palladium catalyzed decarboxylative asymmetric alkylation took place in the presence of a chiral PHOX ligand. The scope of the reaction was studied varying substituents on acyclic alpha-allylketones and an additive effect was noticed with respect of the reaction rate and selectivity. In addition to the preparation of molecules with pharmaceutical interest, few experiments to elucidate the role of the additive in the allylation reaction were investigated. Inspired by our observation of quinonoid formation and our use of the palladium asymmetric allylation method to generate an alpha-stereogenic center, we anticipated that a diastereoselective synthesis of a key intermediate for the synthesis of aliskiren could be accomplished by introducing a nucleophile on a quinonoid intermediate from the least hindered face, under catalytic and acidic conditions. Gold(III) chloride and bismuth(III) triflate were found to be especially efficient as catalysts, showing kinetically controlled differentiation in the reactivity of diastereomeric alpha-substituted benzyl alcohols.
152

Sword of the Sun: Marshal Boufflers and the Experience of War in the Grand Siècle

Beckman, Steven Andrew, Jr 24 August 2022 (has links)
No description available.
153

The child’s perspective of war and its aftermath in works of adult prose and film in Mexico and Spain

Nickelson-Requejo, Sadie 01 June 2011 (has links)
This dissertation investigates the literary and cinematic use of the child’s perspective to present the Mexican Revolution and the Spanish Civil War and their aftermath in several Mexican, Spanish, and international (Mexican-Spanish collaborative) narratives of the 20th and early 21st Centuries written by adult authors and filmmakers, and targeted for adult audiences. The Mexican narratives are Cartucho and Las manos de mamá by Nellie Campobello, Balún Canán by Rosario Castellanos, and Bandidos, a film by Luis Estrada; selected Spanish works are El espíritu de la colmena by Víctor Erice, Cría cuervos by Carlos Saura, and El sur by Adelaida García Morales; and both international works are films by Guillermo del Toro, El espinazo del diablo and El laberinto del fauno. I attempt to determine the textual or cinematic function of the child as first person (homodiegetic) narrative viewer in these works, and I study the different ways in which this child’s point of view is constructed in order to depict the overwhelming tragedy of war. I note patterns and diversities in subject matter presented by the narrative voice, and observe the characteristics of the child narrative viewer’s world and priorities (as presented by the authors and filmmakers), paying careful attention to how each perceives and understands his or her country’s violent upheaval and its aftermath. The theoretical framework of this investigation draws mainly from trauma theory, Gothic studies, and the tradition of the fairy tale. I illustrate how within the war narrative in addition to the author’s/filmmaker’s desire to recreate the sentiment that a child would evoke in adult readers and viewers, the child narrative viewer is employed for three main reasons: to play upon or against preexisting notions of the child’s innocence; to represent (possibly subversively) the nation; and as therapeutic means of returning to a paradise lost or creating a paradise never experienced. / text
154

Partner satisfaction and renewal likelihood in consumer supported agriculture (CSA) : a case study of The Equiterre CSA network

Achuo, George January 2003 (has links)
No description available.
155

Partner satisfaction and renewal likelihood in consumer supported agriculture (CSA) : a case study of The Equiterre CSA network

Achuo, George January 2003 (has links)
No description available.

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