The direct conversion of carbon–hydrogen bonds into valuable carbon-carbon and carbon-heteroatom bonds is a significant challenge to synthetic organic chemists. More than ever, chemists are employing Rh(III)-catalysts bearing cyclopentadienyl (Cp) ligands to transform otherwise inert C–H bonds. Furthermore, manipulating the sterics and electronics of the Cp ligand show significant impact on catalytic transformations. Our group has developed a library of CpˣRh(III)-precatalysts in hopes of enhancing known reactivity as well as discovering new C–H bond functionalizations. We have previously reported that N-enoxyphthalimides are a unique one-carbon component for the cyclopropanation of activated alkenes. In an effort to expand the scope to accessible alkenes, we have found a number of symmetrical unactivated alkenes undergo [2+1] annulation to afford intriguing spirocyclic cyclopropanes. Additionally, we have developed a Rh(III)-catalyzed diastereoselective [2+1] annulation onto allylic alcohols to furnish substituted cyclopropyl ketones. Notably, the traceless oxyphthalimide handle serves three functions: directing C–H activation, oxidation of Rh(III), and, collectively with the allylic alcohol, in directing cyclopropanation to control diastereoselectivity. Allylic alcohols are shown to be highly reactive olefin coupling partners leading to a directed diastereoselective cyclopropanation reaction, providing products not accessible by other routes. Next, an artifact of previous cyclopropanation reactions leads to the formation of a Rh-π-allyl complex. Attempts at 1,1-carboamination of alkenes are made using alkenes and nitrenoid precursors toward the 3-component synthesis of allylic amines. Stoichiometric studies help elucidate the mechanism and challenges. Lastly, efforts toward 1,2-carboamination of alkenes initiated by sp³ C–H bond activation are made with two different reactivity manifolds. Isolation of reaction intermediates are discussed as well as providing viable paths toward valuable products.

Made available in DSpace on 2014-12-17T14:09:14Z (GMT). No. of bitstreams: 1 LuisFL_TESE.pdf: 1981587 bytes, checksum: 1da0819bc859b1e23958de0190156279 (MD5) Previous issue date: 2012-04-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, biodiesel was produced from castor oil that was a byproduct glycerin. The molar ratio between oil and alcohol, as well as the use of (KOH) catalyst to provide the chemical reaction is based on literature. The best results were obtained using 1 mol of castor oil (260g) to 3 moles of methyl alcohol (138g), using 1.0% KOH as catalyst at a temperature of 260 ? C and shaken at 120 rpm. The oil used was commercially available, the process involves the reaction of transesterification of a vegetable oil with methyl alcohol. The product of this reaction is an ester, biodiesel being the main product and the glycerin by-product which has undergone treatment for use as raw material for the production of allyl alcohol. The great advantage of the use of glycerin to obtain allyl alcohol is that its use eliminates the large amount of waste of the biodiesel and various forms of insult to the environment. The reactions for the formation of allyl alcohol was conducted from formic acid and glycerin in a ratio 1/1, at a temperature of 260oC in a heater blanket, being sprayed by a spiral condenser for a period of 2 hours and the product obtained contains mostly the allylic alcohol .. The monitoring of reactions was performed by UV-Visible Spectrophotometer: FTIR Fourier transform, the analysis showed that these changes occur spectrometer indicating the formation of the product allylic alcohol (prop-2-en-1-ol) in the presence of water, This alcohol was appointed Alcohol GL. The absorption bands confirms that the reaction was observed in (? C = C) 1470 -1600 cm -1 and (? CO), 3610-3670 attributed to C = C groups and OH respectively. The thermal analysis was carried out in a thermogravimetric analyzer SDT Q600, where the mass and temperature are displayed against time, that allows checking the approximate rate of heating. The innovative methodology developed in the laboratory (LABTAM, UFRN), was able to treat the glycerine produced by transesterification of castor oil and used as raw material for production of allyl alcohol, with a yield of 80%, of alcohol, the same is of great importance in the manufacture of polymers, pharmaceuticals, organic compounds, herbicides, pesticides and other chemicals / Neste trabalho o biodiesel foi produzido a partir de ?leo de mamona que teve como subproduto a glicerina. A raz?o molar entre ?leo e ?lcool, bem como o uso do (KOH) como catalisador qu?mico para proporcionar a rea??o, foi baseada em dados da literatura. Os melhores resultados foram obtidos, utilizando 1 mol de ?leo de mamona (260g) para 3 mols de ?lcool met?lico (138g). O ?leo utilizado foi adquirido comercialmente, o processo de transesterifica??o envolve a rea??o do ?leo vegetal com um ?lcool met?lico. O produto dessa rea??o ? um ?ster, sendo o biodiesel o seu principal produto e a glicerina o sub-produto a qual foi submetida a tratamento para uso como mat?ria-prima para a obten??o do ?lcool al?lico. A grande vantagem do uso da glicerina para obten??o de ?lcool al?lico ? que sua utiliza??o elimina a grande quantidade de res?duos do biodiesel e v?rias formas de agress?o ao meio ambiente. As rea??es para forma??o do ?lcool alilico foram conduzidas a partir de ?cido f?rmico e glicerina, em uma raz?o 1/1, sob temperatura de 260oC, em uma manta aquecedora, sendo vaporizado por um condensador em espiral por um per?odo de 2 horas, e o produto obtido contem em sua grande maioria o ?lcool al?lico. O acompanhamento das rea??es foi realizado por Espectrofot?metro UV-Vis?vel: FTIR com transformada de Fourier, a an?lise revelou que estas altera??es espectrom?tricas ocorrem indicando a forma??o do produto ?lcool al?lico (prop-2-en-1-ol), em presen?a de ?gua, este ?lcool foi nomeado de ?lcool GL. As bandas de absor??o que confirmam a rea??o foram observadas em (? C=C) em 1470 -1600 cm-1 e em (? C-O), 3610 3670 atribu?das aos grupos C=C e O-H respectivamente. A analise t?rmica foi realizada em um analisador Termogravim?trico SDT Q600, onde a massa e a temperatura ser?o exibidos em fun??o do tempo, isto permite a verifica??o aproximada da taxa de aquecimento. A metodologia inovadora desenvolvida no laborat?rio (LABTAM, UFRN), foi capaz de tratar a glicerina produzida, atrav?s da transesterifica??o de ?leo de mamona e utilizar como mat?ria prima para produ??o do ?lcool al?lico, apresentando um rendimento de 80%, deste ?lcool, o mesmo ? de grande import?ncia na fabrica??o de pol?meros, medicamentos, compostos org?nicos, herbicidas, pesticidas e outros produtos qu?micos

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A viabilidade econÃmica da produÃÃo do biodiesel depende do uso do glicerol, subproduto com estrutura multifuncional, considerado matÃriaâprima bio-renovÃvel, de grande potencial para ser transformado a combustÃveis ou produtos quÃmicos de maior valor agregado. Com o intuito de contribuir para o desenvolvimento dessa linha de pesquisa, foi realizado estudo do potencial catalÃtico da γ-Al2O3 modificada com Ãxido de molibdÃnio e promotores (Cu, Ni ou Co), na reaÃÃo de desidrataÃÃo do glicerol a intermediÃrios quÃmicos com aplicaÃÃo industrial. A estratÃgia foi sintetizar esferas de Al2O3 por mÃtodo hÃbrido, as quais apresentam interessantes propriedades estruturais, texturais e quÃmicas para em seguida impregnar com precursores dos metais via mÃtodo nÃo-convencional (Pechini). A composiÃÃo dos materiais foi escolhida com o objetivo de avaliar o efeito bifuncional causado pela combinaÃÃo das propriedades Ãcido/bÃsicas e redox de catalisadores de molibdÃnio suportado em alumina. Para fins comparativos foi testado catalisador comercial Ni-Mo/Al2O3 com elevada acidez e porosidade. Os catalisadores foram caracterizados por: ICP-OES, FRX, TGA/DTA, DRX, MEV, IV, TPR-H2, TPD-CO2, isotermas de adsorÃÃo/dessorÃÃo de N2, e acidez atravÃs de adsorÃÃo de piridina. O desempenho dos catalisadores foi avaliado na desidrataÃÃo do glicerol, sob fluxo de N2 ou H2, a 1atm e 250ÂC. As mudanÃas na atividade e seletividade devido à troca do gÃs de arraste estÃo associadas a alteraÃÃes nas propriedades Ãcido/redox dos catalisadores, como sugerido pelas medidas de acidez e TPR-H2. AcroleÃna foi o principal produto observado para todos os catalisadores, porÃm a amostra contendo cobre (CuMoAl), mostrou maior atividade catalÃtica e superior seletividade a Ãlcool alÃlico, bem como produÃÃo do 1-propanol; o que està associado a transferÃncia de hidrogÃnio. Essa seletividade concorda com resultados de TPR-H2, que mostram maior influÃncia do cobre sobre a reduÃÃo do Ãxido de molibdÃnio, quando comparado aos promotores (Co ou Ni). Ao final sÃo propostos passos reacionais envolvidos na conversÃo do glicerol a Ãlcool alÃlico. / The economic viability of biodiesel production depends of the use of glycerol, by-product with multifunctional structure, considered a bio-renewable feedstock of great potential to be transformed to fuel or higher value-added chemicals products. In order to contribute to the development of this research area, study was carried out in order to explore the catalytic potential γ-Al2O3 modified with molybdenum oxide and promoter (Cu, Ni or Co) in the glycerol dehydration reaction to chemical intermediates with industrial application was performed. The strategy was to synthesize Al2O3 spheres by hybrid method with interesting structural, textural and chemical properties for then impregnating with precursors of metals via unconventional method (Pechini). The material composition was chosen with the aim of evaluating the bifunctional effect caused by the combination of acid-base and redox properties of molybdenum catalysts supported on alumina. For comparison was evaluated commercial Ni-Mo/Al2O3 catalyst with high acidity and porosidade. The catalysts were characterized for: ICP-OES, XRF, TGA/DTA, XRD, SEM, IR, H2-TPR, TPD-CO2, N2 adsorption/desorption isotherms, and acidity measurements through pyridine adsorption. The catalytic performance was evaluated in the glycerol dehydration under N2 or H2 flow at atmospheric pressure and 250ÂC. The modification in the activity and selectivity due to the change of carrier gas are attributed to the changes of acid/redox properties of the catalyst, as suggested by acidity measurements and TPR-H2. Acrolein was the main product observed for all catalysts, but the cupper containing catalyst (CuMoAl) showed higher catalytic activity and, and superior selectivity to allyl alcohol, as well as the production of 1-propanol, which is due to the hydrogen transfer. This selectivity agrees with H2-TPR results, which show stronger effect of the copper over the molybdenum oxide reduction, if compared to the others promoter (Co or Ni). At the end it is proposed the reaction steps mechanism for the glycerol conversion to allyl alcohol.