Le développement d’une chimie propre et donc durable est un des challenges majeurs du 21ème siècle dans les pays industrialisés. Étant au cœur de nombreuses découvertes dans divers domaines scientifiques allant de la physique à la médecine, les sciences chimiques doivent jouer un rôle central pour résoudre un certain nombre de problèmes environnementaux auxquels nous devons faire face. Mon travail de thèse s’inscrit dans cette problématique par le développement de méthodologies de synthèse faisant intervenir plusieurs transformations dans le même réacteur. Nous avons notamment développé des séquences réactionnelles appelées HRC (pour Heck-Reduction-Cyclization, en anglais) prenant appui sur le caractère multi-tâche d’un catalyseur à base de palladium. Ces travaux nous ont permis de préparer une grande variété d’hétérocyles ou composés fonctionnalisés parmi lesquels nous pouvons citer les oxindoles, les indanones, ou encore les naphthoxindoles. Ces travaux ont donné lieu pour le moment à quatre publications dans des journaux à comité de lecture. / The development of clean chemistry and therefore sustainable is one of the major challenges of the 21st century in industrialized countries. Being in the heart of many discoveries in various scientific fields ranging from physics to medicine, the chemical sciences must play a central role in solving a number of environmental problems we face. My thesis work is part of this problem through the development of synthetic methodologies involving several transformations in the same reactor. We have developed the reaction sequences called HRC (for Heck-Reduction-cyclization) building on the multi-task of a palladium catalyst. This work allowed us to prepare a variety of functionalized heterocycles or compounds from which we can cite the oxindole, the indanones, or the naphthoxindoles. This work has resulted for the time four publications in peer-reviewed journals.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work describes a methodology of controlled synthesis of block copolymers by one-pot reactions involving simultaneous RAFT and ROP processes mediated by a bifunctional compound which acts as a chain transfer agent (CTA) for the RAFT process and co-initiator of the ROP process. Reactions involving the RAFT of Styrene (St) and the ROP of ε-Caprolactone (ε-CL) were performed to obtain PS-b-PCL diblock copolymers. The catalysts Sn(Oct)2 and diphenyl phosphate (DPP) were evaluated in the ROP process. Diphenyl phosphate is the most appropriate for this kind of reaction, since Sn(Oct)2 proved to be avid when interacted with CTA, interfering antagonistically in the radical equilibrium of the RAFT process. The reactions were always controlled when DPP was used as a ROP catalyst, wherein copolymers with narrow molar mass distribution were obtained in the end. This methodology was employed in the synthesis of other linear and graft amphiphilic block copolymers, proving to be an excellent alternative for this purpose. Thermoresponsive copolymers based on Poly(oligo(ethylene glycol)methyl ether methacrylate) (POEGMA) and pH responsive based on Poly(acrylic acid) (PAA) were obtained. The physicochemical properties of the copolymers were investigated in solid state as well as in solution, and the results are in total agreement with values reported in the literature. / Este trabalho descreve uma metodologia de síntese controlada de copolímeros em bloco por reações one-pot envolvendo processos RAFT e ROP simultâneos, mediados por um composto bifuncional que atua como agente de transferência de cadeia (CTA) para o processo RAFT e co-iniciador do processo ROP. Reações envolvendo a RAFT do estireno (St) e a ROP da ε-Caprolactona (ε-CL) foram realizadas para obter copolímeros dibloco PS-b-PCL. Os catalisadores Sn(Oct)2 e difenil fosfato (DPP) foram avaliados, sendo o último o mais apropriado para este tipo de reação, uma vez que Sn(Oct)2 mostrou-se ávido por interações com o CTA, interferindo antagonicamente no equilíbrio de radicais do processo RAFT. As reações mantiveram o caráter controlado quando DPP foi usado como catalisador ROP, sendo que ao final, copolímeros com estreita distribuição de massa molar foram obtidos. Esta metodologia foi empregada na síntese de outros copolímeros em bloco anfifílicos lineares e enxertados, se mostrando uma excelente alternativa para este propósito. Copolímeros termoresponsivos à base de Poli(metacrilato de poli(etilenoglicol)metil éter) (POEGMA) e pH responsivos à base de Poli(ácido acrílico) (PAA) foram obtidos. As propriedades físico-químicas dos copolímeros foram investigadas em estado sólido e em solução, e os resultados estão em plena concordância com valores relatados na literatura.

Made available in DSpace on 2014-12-17T14:55:44Z (GMT). No. of bitstreams: 1 PauloVS_DISSERT.pdf: 1338370 bytes, checksum: 7f4728ef2faffa30200a5b0daf963f20 (MD5) Previous issue date: 2010-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work describes the experimental implementation of a shunt active power filter applied to a three-phase induction generator. The control strategy of active filter turned to the excitation control of the machine and to decrease the harmonics in the generator output current. Involved the implementation of a digital PWM switching, and was made a comparison of two techniques for obtaining the reference currents. The first technique is based on the synchronous dq reference method and the second on the theory of instantaneous power. The comparison is performed via simulation and experimental results. To obtain the experimental results, was mounted a bench trial and the control and communications needed were implemented using DSP - MS320F2812. The simulation results and experimental data proved the efficiency of the filter to apply, highlighting the technique of instantaneous power / Este trabalho descreve a implementa??o experimental de um filtro ativo paralelo de pot?ncia aplicado a um gerador de indu??o trif?sico. A estrat?gia de controle do filtro ativo voltou-se para o controle de excita??o da m?quina e para a minimiza??o dos harm?nicos na corrente de sa?da do gerador. Envolveu a implementa??o de um chaveamento PWM digital, tendo sido realizada a compara??o de duas t?cnicas para obten??o das correntes de refer?ncia. A primeira t?cnica se baseia no m?todo referencial s?ncrono dq e a segunda na teoria das pot?ncias instant?neas. A compara??o ? realizada via simula??o e resultados experimentais. Para obten??o dos resultados experimentais, foi montada uma bancada experimental e o controle e comunica??es necess?rias foram implementados utilizando-se um DSP - TMS320F2812. Os resultados de simula??o e experimentais obtidos comprovaram a efici?ncia do filtro para a aplica??o, com destaque para a t?cnica das pot?ncias instant?neas

Les 5-hydroxy-1H-pyrrol-2(5H)-ones ou y-hydroxybutyrolactames sont des composés synthétiques intéressants puisque ces hétérocycliques sont non seulement présents dans un grand nombre de produits naturels, mais sont aussi des briques moléculaires en synthèse organique. L'objectif principal de ce travail a été de développer un processus général et rapide pour préparer les y-hydroxybutyrolactams à partir de produits de départ facilement disponibles ou commerciaux.Ce travail a d'abord été axé sur la synthèse de y-hydroxybutyrolactames via une réaction multicomposée entre des acides (Z)-β-iodo-α,ß-insaturés, des alcynes terminaux et des amines primaires en présence d'une catalyseur de cuivre. Cette méthode s’est avérée rapide et générale et a permis les synthèses de diverses y-hydroxybutyrolactames fonctionnalisés. Cette méthode a également été appliquée à la synthèse totale d’un produit naturel, la pulchellalactame (inhibiteur de la protéine tyrosine phosphatase CD45). Pour finir, une synthèse « one-pot » des composés y-alkylidenebutyrolactames, polyheterocyclics et spirolactames a été réalisée via la formation d’un N-acyliminium. / 5-Hydroxy-1H-pyrrol-2(5H)-ones or γ-hydroxybutyrolactams are interesting synthetic targets since these heterocyclic scaffolds are not only present in a large number of natural products, but also they are versatile building blocks in organic synthesis. The main goal of this work was to develop a general and straightforward process to prepare γ-hydroxybutyrolactams from readily and commercially available starting materials. This work was initially focused on the synthesis of γ-hydroxybutyrolactams via a multicomponent process involving (Z)-β-iodo-α,β-unsaturated acids, terminal alkynes and primary amines in the presence of copper catalyst. This method was found to be rapid and general to access highly functionalized γ-hydroxybutyrolactams. This method was also applied in the total synthesis of natural product namely pulchellalactam (CD45 protein tyrosine phosphatase inhibitor). In addition, taking the potential of γ-hydroxybutyrolactams as N-acylimminium (NAI) equivalent allowed us to construct γ-alkylidenebutyrolactam, polyheterocyclic and spirolactam compounds in one-pot approach.

The goal of this study is to present kinetic studies of (co)polymerization as well as the synthesis and characterization of amphiphilic copolymers with a fluorinated segment. Copolymers were obtained by RAFT (co)polymerizations using one-pot and miniemulsion methods. Different monomers were used to obtain stable selforganized systems, being that one of them was always fluorinated. The resulting copolymers showed different properties, especially when evaluating their selforganization. For this reason, different methodologies for self-organization were used, depending on the synthetic route by which the copolymers were obtained. The self-organization systems formed by the fluorinated amphiphilic copolymers were analyzed by dynamic light scattering (DLS) to determine the size and distribution of the species. The micellar systems analyzed showed great potential for the use in diagnostic imaging, which makes it possible to identify the presence of fluorine in the interior of the micelles through 19F NMR analysis. Relaxation times T1 were measured and values were similar to those reported in the literature. To reinforce the above statement, we performed cell viability assays, which demonstrated the biocompatibility of fluorinated amphiphilic copolymers. / O objetivo deste trabalho é apresentar estudos cinéticos de (co)polimerizações bem como a síntese e a caracterização de copolímeros anfifílicos contendo um segmento fluorado, os quais foram obtidos através de (co)polimerizações RAFT pelos métodos one-pot e miniemulsão. Diferentes monômeros foram utilizados para a obtenção de sistemas auto-organizados estáveis, sendo um deles sempre fluorado. Os copolímeros resultantes apresentaram propriedades distintas, principalmente quando se avalia a autoorganização dos mesmos. Por este motivo, diferentes metodologias para autoorganização foram utilizadas, dependendo da rota sintética pela qual os copolímeros foram obtidos. Os sistemas auto-organizados formados pelos copolímeros anfifílicos fluorados foram analisadas por espalhamento de luz dinâmico (DLS) para determinação de tamanho e distribuição das espécies. Os sistemas micelares analisados apresentaram grande potencial para utilização em diagnósticos por imagens sendo possível identificar a presença de flúor no interior das micelas através de análises por RMN 19F. Os tempos de relaxação T1 foram medidos e os valores encontrados foram semelhantes aos reportados na literatura. Para reforçar a afirmação acima, foram realizados ensaios de viabilidade celular que demonstraram a biocompatibilidade dos copolímeros anfifílicos fluorados.

L'élaboration de méthodes de synthèse, basées sur l’utilisation d’espèces métalliques a été un sujet de tous les instances en chimie organique. Malgré l’efficacité des métaux utilisés en catalyse homogènes, leurs procédures de recyclage restent limitées. Ce pourquoi, une contrainte supplémentaire a été placée dans la conception de catalyseurs, pouvant offrir à la fois l'efficacité de la catalyse homogène et le recyclage de l’hétérogène. Dans ce contexte, les nanoparticules métalliques sont apparues comme objet phare, en raison de leurs propriétés physico-chimiques inégalées. On a découvert que les nanoparticules de métaux nobles présentaient des propriétés catalytiques similaires dans certains cas, aux complexes monoatomiques. De plus, les Au NPs ont montré une activité catalytique remarquable dans l'oxydation d’alcools activés sous O2. Nous avons donc envisagé des procédures multicatalytiques, basées sur les NPs d’Au. Notre choix d'utiliser des catalyseurs solides était pertinent, puisque les nano-catalyseurs, pour lesquels la fraction de sites actifs se trouve en surface, limitent les risques de cross-quenching. Ici, nous présentons trois nouveaux procédés bicatalytiques permettant l’accès, à des chromenes/quinoléines (53-93%) via une oxydation / Michael Addition/ aldolisation, combinant nanocatalyse et catalyse basique, l’accès à des ortho-THC (50-81%) via oxydation / arylation / cyclisation, combinant nanocatalyse et catalyse supportée, ainsi qu’une une oxydation / hydrolyse en cascade, pour accéder à l’HMLA (86%, sel 93%), un grand panel de produits d'activité biologique reconnue, utilisé en parfumerie ou visant une pré-industrialisation via la chimie en flux continu. / Elaboration of synthetic methods based on metal-catalyzed reactions has been a hot topic in organic chemistry. Despite good efficiency, catalysis proceeding homogeneously, are limited in the operation of recovering/recycling of the catalysts. An important stress was placed to design catalysis, offering both the efficiency of homogeneous catalysts and the recyclability of heterogeneous catalysts. In this context, metal nanoparticles merged as a key tool, due to their unique physical and chemical properties. Notably, Au NPs have shown remarkable catalytic activity in the oxidation of activated alcohols under O2 atmosphere. Since now, the access to more complex molecules is the next step forward for this field, we envisioned multicatalytic roads, based on the oxidation of activated alcohols via supported Au NPs. Our choice of using solid catalysts was relevant, since nanostructured catalysts for which the fraction of active sites are located on the surface, limit the risk of cross-quenching. The latter carbonyl formed, could be further converted in situ, via tandem protocol. Herein, we developed novel, atom- and step-economical bicatalytic one-pot processes, to access substituted chromenes/quinolines (53-93%) by tandem oxidation/hetero-Michael addition/aldolisation combining nanocatalysis and base catalysis, ortho-THCs (50-81%) via tandem oxidation/arylation/cyclisation combining nanocatalysis and supported catalysts and a tandem cascade oxidation/hydrolysis to access HMLA (86%, sel 93%). A large panel of products of biological activity relevance, pertaining to the fragrance chemistry or aiming in some cases, pre-industrial scalability via continuous flow applications.

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Why does mass-violence happen at all? This paper takes the first steps to establish a model to answer this question and explain extreme mass-violence as a phenomenon. This paper seeks to fill a gap in the field of research, in which models exist to explain the phenomenon of violence, with cases of genocide being seen as problems or exceptions, and as such researched as individual cases rather than as part of a wider phenomenon. This paper uses a selected part of the writings of Theodor Adorno and Max Horkheimer to establish the basis for a model to explain extreme-cases of mass-violence. The Five-Pillar Model includes 5 social elements - (1) Culture Industry (2) Mass-Media (3) Propaganda (4) Dehumanization (5) Ideological Awareness. When these pillars all reach a high enough level of severity, conditions enable elites to use scapegoating - to divert revolutionary attention to a specific puppet group, resulting in extreme mass-violence. The Five-Pillar Model is then used to analyze an empirical case - Cambodia 1975-1979 and shows how these pillars all existed in an extreme form in that case. This paper presents scapegoating as a possible explanation for the Cambodian case.

Perennial growers overwintering plant stock require information to assist in deciding which containerized plants are most likely to successfully overwinter. Three studies on container-grown herbaceous perennials were conducted to examine the influence of plant age, soil moisture, and temperature cycling date on cold hardiness. In January, plants were exposed to controlled freezing temperatures of -2, -5, -8, -11, and -14C and then returned to a 3-5C greenhouse. In June, plants were assessed using a visual rating scale of 1-5 (1 = dead, 3-5 = increasing salable quality, varying by cultivar) and dry weights of new growth were determined. Controlled freezing in November and March were also included in the third study. In the first study, two ages of plants were exposed to controlled freezing temperatures in January. For Geranium x cantabrigiense 'Karmina', age had no effect on either rating or dry weight in one study year. In two Sedum 'Matrona' study years, age had no effect on dry weight but ratings were higher for older plants than younger plants in the first year and higher for younger plants than older plants in the second year. In two Leucanthemum x superbum 'Becky' study years, age had an effect on both rating and dry weight which were both generally higher for younger plants than older plants. In the second study, plants were maintained in pots at two different soil moisture levels prior to exposure to controlled freezing temperatures in January. Coreopsis 'Tequila Sunrise' and Carex morrowii 'Ice Dance' showed no effect on either rating or dry weight from soil moisture level. Soil moisture level had no effect on dry weight but ratings were higher for Geranium x cantabrigiense 'Cambridge' “wet” plants and for Heuchera 'Plum Pudding' “dry” plants. Carex laxiculmus 'Hobb' (Bunny Blue™) soil moisture level had an effect where dry weight was higher for “dry” plants. Means at were of salable quality for Geranium and Heuchera at all temperatures and Carex laxiculmus at temperatures above -11C. The effects of soil moisture level on Carex oshimensis were inconclusive. In the third study, during November, January, and March, plants were subjected to temperature cycling treatments prior to exposure to controlled freezing temperatures. Geranium x cantabrigiense 'Cambridge' were more tolerant of both temperature cycling and freezing temperatures in January and an increased number of cycles in November had an advantageous effect. Sedum 'Matrona' were more tolerant of temperature cycling and freezing temperatures in January and an increased number of cycles in March had an advantageous effect. Leucanthemum x superbum 'Becky' were more tolerant of temperature cycling in January in the second year of the study and an increased number of cycles in November had an advantageous effect in the first year and in all months in the second year. Overwintering younger container-grown plants is likely to result in more growth and higher quality following exposure to freezing temperatures. Effects of soil moisture level on overwintering container-grown plant growth and quality are cultivar-specific and a general effect could not be established in these studies. Overwintering container-grown plants are likely to be hardier in January and slight temperature cycles prior to exposure to freezing temperatures generally increase hardiness.