Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-11-29T18:26:31Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Cibeli May.pdf: 3927669 bytes, checksum: 83b271f172e7367bd94016252ee517c4 (MD5) / Made available in DSpace on 2018-11-29T18:26:31Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Cibeli May.pdf: 3927669 bytes, checksum: 83b271f172e7367bd94016252ee517c4 (MD5) Previous issue date: 2018-04-13 / O texto deste trabalho esta dividido em três capítulos. No Capítulo 1 tem-se a revisão bibliográfica onde é apresentada a aplicação dos compostos orgânicos bromados, a principal forma de síntese destes e as mudanças que vêm ocorrendo devido o uso de solventes prejudiciais à camada de ozônio. Serão descritos métodos alternativos de sínteses, sendo que o mais abordado é o método eletroquímico usado, portanto neste trabalho, por meio do qual é possível realizar a bromação de anéis aromáticos e bromação de aromáticos na posição benzílica. Também serão apresentadas as aplicações dos compostos sintetizados: α, α α’, α’-tetrabromo-pxileno e α, α, α’, α’-tetrabromo-2,5-diciano-p-xileno. No Capítulo 2 são apresentados os estudos experimentais e teóricos, onde se buscou uma explicação para as diferenças observadas na reação química tradicional de tetrabromação benzílica no 2,5-diciano-p-xileno em comparação ao p-xileno. Para isso se realizou para cada composto a reação de Wohl-Ziegler por 10 horas, recolhendo-se amostras em cada tempo determinado, estas amostras formam analisadas por Ressonância Magnética Nuclear de Hidrogênio (RMN de H1) e Cromatografia Gasosa acoplada a Espectrometria de Massas (CG-MS). Também foi realizado um estudo teórico de carga a partir de simulação computacional. O que se observa é que o composto contendo o substituinte nitrila apresenta uma reação de bromação mais lenta com a formação de quatro compostos intermediários, enquanto que para o composto sem substituinte a reação é mais rápida e apenas dois compostos intermediários são observados. No Capítulo 3 é descrito um método alternativo de síntese para a tetrabromação benzílica do 2,5-diciano-p-xileno e do p-xileno. A obtenção destes compostos ocorre usando-se reações eletroquímicas, onde não é necessário o uso de solventes de venda proibida (CCl4). Também se realizou um acompanhamento cinético, analisando-se as amostras coletadas por RMN de H1 e CG-MS, para fazer a comparação de síntese pelo método tradicional e eletroquímico. Sendo que a principal diferença observada é que no método eletroquímico as reações são mais lentas, também com este método é possível continuar adicionando bromos na posição benzílica ao composto p-xileno, obtendo-se este composto pentabromado e hexabromado. / The text of this paper is divided into three chapters. In Chapter 1 there is a bibliographic review where the application of brominated organic compounds is presented, the main form of synthesis of these and the changes that have been occurring due to the use of solvents harmful to the ozone layer. It will be described alternative methods of synthesis, and the most approached is the electrochemical method used, therefore in this work, through which it is possible to perform the bromination of aromatic rings and bromination of aromatics in the benzylic position. The applications of the synthesized compounds: α, α, α', α'-tetrabromo-p-xylene and α, α, α ', α'-tetrabromo-2,5-dicyano-p-xylene will also be presented. In Chapter 2 we present experimental and theoretical studies, where an explanation was sought for the differences observed in the traditional chemical reaction of benzylic tetrabromination in 2,5-dicyano-p-xylene compared to p-xylene. In order to do this, the reactions of Wohl-Ziegler were carried out for 10 hours. Samples were collected at each determined time. These samples were analyzed by Hydrogen Nuclear Magnetic Resonance (H1 NMR) and Gas Chromatography Coupled to Mass Spectrometry (CG-MS). A theoretical load study was also carried out from a computer simulation. What is observed is that the compound containing the nitrile substituent has a slower bromination reaction with the formation of four intermediate compounds, whereas for the compound without substituent the reaction is faster and only two intermediate compounds are observed. In Chapter 3 an alternative method of synthesis for the benzylic tetra-bromination of 2,5-dicyano-p-xylene and p-xylene is described. The production of these compounds occurs using electrochemical reactions, where it is not necessary to use solvents of prohibited sale (CCl4). Also, a kinetic monitoring was performed, analyzing the samples collected by H1 NMR and CG-MS, to make the comparison of synthesis by the traditional and electrochemical method. As the main difference observed is that in the electrochemical method the reactions are slower, also with this method it is possible to continue adding bromines in the benzylic position to the compound p-xylene, obtaining this compound pentabromado and hexabromado.

Bien que thermodynamiquement et cinétiquement stable, le dioxyde de carbone est une molécule qui peut être convertie en carbonates cycliques à cinq ou six atomes respectivement au départ d’époxydes ou d’oxétanes moyennant l’utilisation d’un catalyseur approprié. Ces carbonates cycliques sont utilisés comme solvants verts, électrolytes pour les batteries au lithium ou comme intermédiaires pour la synthèse de polymères. Cependant, les performances catalytiques doivent être améliorées en particulier pour lecouplage du CO2 avec les huiles végétales époxydées ou les oxétanes. Dans ce contexte, nous avons développé un nouveau catalyseur homogène bicomposant organique composé d’un sel d’ammonium jouant le rôle de catalyseur et d’un co-catalyseur fluoré simple ou double donneur de liaison hydrogène. Dans un premier temps, l’efficacité de ces nouveaux catalyseurs a été évaluée et optimisée pour le couplage entre un époxyde terminal et le CO2 via des études cinétiques par spectroscopie FTIR ou Raman in-situ sous pression. Ces études ont démontré que l’utilisation combinée de sels d’ammonium et d’alcools fluorés induit un effet synergique permettant la fixation rapide et sélective du CO2 sur les époxydes modèles et les huiles végétales époxydées dans des conditions douces et sans solvant. L’utilisation de cette plateforme catalytique performante a ensuite été exploitée pour la synthèse d’oligocarbonates hydroxyles téléchéliques au départ d’oxétanes nettement moins réactifs que les époxydes. Ces oligocarbonates ont finalement été valorisés pour la synthèse de polyuréthanes CO2-sourcés par extension de chaines en présence de diisocyanates. En complément de ces travaux, une compréhension fine des mécanismes réactionnels a été réalisée via calculs DFT qui ont mis en évidence que l’efficacité catalytique de ces catalyseurs était liée à la stabilisation multiple des intermédiaires et états de transition par liaisons hydrogènes. A ce jour, via une étude comparative, nous avons mis en évidence que ce système catalytique bicomposant constitue un des catalyseurs organiques les plus performants pour le couplage du CO2 et d’époxydes et le seul système organique permettant la conversion d’oxétanes en synthons d’intérêt. / Although it is a thermodynamically and kinetically stable molecule, carbon dioxide can beconverted into five- and six-membered cyclic carbonates by coupling with epoxides or oxetanes, respectively, using appropriate catalysts. Cyclic carbonates are used as green solvents, electrolytes for Liion batteries or intermediates for the synthesis of polymers. However, the catalytic performance must be further enhanced in particular for the coupling of CO2 with epoxidized vegetable oils or oxetanes. In this context, we developed a new highly efficient bicomponent homogeneous organocatalyst composed of anammonium salt as the catalyst and fluorinated single or double hydrogen bond donors as co-catalysts. First,a screening of onium-based catalysts and hydrogen-bond donors was performed. Performances of thecatalysts and optimization of the reaction was realized through detailed kinetics studies using in-situ FTIR/Raman spectroscopy under pressure. We demonstrated that fluorinated alcohols showed unexpected co-catalytic activity due to synergisms between the onium salt and fluorinated co-catalysts enabling the fast and selective addition of CO2 on to model epoxides and epoxidized vegetable oils under solvent-free and mild experimental conditions. The use of this powerful dual catalyst was then extended to the first organocatalytic coupling of CO2 with less reactive oxetanes to produce hydroxyl telechelic oligocarbonates that were used asprecursor of CO2-based polyurethanes by chain-extension with a diisocyanate. In addition, a fine comprehension of the mechanisms was investigated by DFT calculations highlighting that the co-catalytic performance of the onium salt/fluorinated alcohol binary catalyst arose from the strong stabilization of the intermediates and transitions states by hydrogen-bonding. To date, through comparative studies, we evidenced that this new catalyst is one