No presente trabalho, métodos analíticos empregando a eletroforese capilar com detecção condutométrica sem contato CE - C4D foram desenvolvidos para a determinação de diversas espécies no biodiesel e etanol combustível. A concentração das espécies inorgânicas (Na+, K+, Ca2+, Mg2+, SO4 2- e PO4 3-) e glicerol no biodiesel são de interesse das agências reguladoras devido à capacidade dessas espécies em formar compostos indesejáveis no motor. A separação dos cátions foi realizada utilizando eletrólito de corrida (BGE) contendo 30 mmol L-1 de Ácido 2-N-morfolino-etanosulfônico (MES) / L-histidina, pH 6. A separação das espécies aniônicas foi realizada em BGE semelhante contendo 0,2 mmol L-1 brometo de cetiltrimetilamônio. Para a determinação do glicerol, que é uma espécie neutra, foi empregada uma etapa de oxidação utilizando periodato. Esta reação é específica para polióis e tem como um dos produtos o iodato. A quantidade de iodato produzida pela reação foi determinada por CE. A separação foi realizada em aproximadamente 1 min, utilizando BGE contendo 30 mmol L-1 de ácido acético, pH 3. Este trabalho também apresenta estudos sobre a formação de ácidos orgânicos de baixo PM durante a etapa de auto-oxidação do biodiesel, uma vez que esta etapa acarreta no aumento da viscosidade e acidez, ocasionando a formação de gomas e sedimentos e, conseqüentemente, o entupimento de filtros de combustíveis. As amostras foram oxidadas utilizando equipamento para teste de oxidação acelerada (Método Rancimat) e CE - C4D foi utilizada para a análise dos produtos iônicos formados. As principais espécies ácidas encontradas foram os ácidos acético e fórmico. Porém, outras espécies são formadas durante esta etapa, tais como os ácidos acrílico, glicólico, glioxílico, láctico e propiônico. Em particular, o ácido glicólico se mostrou uma espécie de grande importância prática, atuando como um marcador do estágio de oxidação do biodiesel, uma vez que este ácido somente é formado após o desencadeamento da auto-oxidação e, além do mais, esta espécie foi observada em amostras de biodiesel de diferentes origens (algodão, soja, palma e sebo bovido). Adicionalmente, métodos para a determinação de Cl-, SO4 2-, formiato, acetato, formaldeído e acetaldeído em etanol combustível são descritos. A separação foi realizada em BGE contendo 20 mmol L-1 de MES / L-histidina e 0,1 mmol L-1 hidróxido de cetiltrimetilamônio, pH 6. Para a separação dos aldeídos por CE, foi realizada a derivatização com bissulfito. O presente trabalho também apresenta um método alternativo para a determinação do teor de água e de álcool em amostras de etanol combustível. A estratégia descrita é baseada na formação de monoalquil carbonatos (MAC) produzidos pela reação de um álcool e o bicarbonato em meio aquoso. / In this work, methods employing capillary electrophoresis with capacitively coupled contactless conductivity detection (CE - C4D) are introduced for the determination of several species in biodiesel and ethanol fuel. The concentrations of inorganic species (Na+, K+, Ca2+, Mg2+, SO4 2-, and PO43-) and glycerol are of interest for the regulatory authorities due to their ability to form undesirable compounds in the engines. The separation of the cations was done in BGE composed of 30 mmol L-1 of 2-N-morpholino-ethanesulfonic acid (MES)/L-histidine, pH 6. The separation of anionic species was carried out in similar BGE including cetyltrimethylammonium bromide (0.2 mmol L-1). For glycerol, a neutral species, its oxidation with periodate was employed. This well-known reaction is specific to polyols and generates iodate. The amount of iodate produced by the reaction was determined by CE. The separation was carried out in ca. 1 min using BGE composed of 30 mmol L-1 of acetic acid, pH 3. This work also presents studies on the formation of low molecular organic acids during the biodiesel autoxidation step. Since the implications of the biodiesel oxidation are the increased viscosity and acidity, causing formation of insoluble gums and sediments that induce the clogging of the fuel filters. The samples were oxidized using equipment for accelerated oxidation test (Rancimat Method) and CE-C4D was used to analyze the ionic products. The main acid species were acetic and formic acids. However, acrylic, glyoxylic, glycolic, lactic, and propionic acids were also observed only after the oxidation step. Thus, these species are candidates for quality markers for biodiesel. In particular, glycolic acid seems to be a good marker, because it is produced only after auto-oxidation started. Moreover, it was found out in biodiesel of different origins (cotton, soy, palm, and animal fat). In addition, alternative methods to determination of Cl-, SO42-, formate, acetate, formaldehyde and acetaldehyde in ethanol fuel are described. The separation was done in BGE composed of 20 mmol L-1 of MES / L-histidine, and 0.1 mmol L-1 cetyltrimethylammonium hydroxide, pH 6. For aldehydes, a neutral species, a derivatization step with bisulfite was employed. The present work also shows an alternative method for analysis of alcohol and water percentage in fuel samples employing CE - C4D in order to achieve the limits established by regulatory authorities. The strategy is based on the formation of monoalkyl carbonates (MAC) produced by the reaction of an alcohol and bicarbonate in aqueous medium.

A quantificação de 11 compostos carbonílicos (formaldeído, acetaldeído, acetona, acroleína, propionaldeído, crotonaldeído, butiraldeído, benzaldeído, isovaleraldeído, valeraldeído e 2,5-dimetilbenzaldeído) e a identificação de outros 43 compostos orgânicos voláteis (alcanos, alcenos, aromáticos, halogenados e nitrogenados) foram feitas em 9 ambientes diferentes de trabalho localizados em áreas internas do Hospital Universitário, USP, São Paulo. Dentre os compostos carbonílicos, os mais abundantes em ordem decrescente foram formaldeído, acetona, acetaldeído e acroleína. As maiores razões de mistura de formaldeído foram observadas nas salas de Macroscopia (169,9 e 90,2 ppbv) e Técnicas Histológicas (11,7 e 58,7 ppbv), em decorrência da atividade desenvolvida nos locais. Na sala de Macroscopia, os níveis de formaldeído encontrados foram acima do limite (100 ppbv) estabelecido por órgãos internacionais que controlam a qualidade do ar em ambientes internos não industriais. As razões de mistura entre o ambiente interno e o ambiente externo, razões I/E, permitiram indicar a predominância dos compostos carbonílicos nos ambientes internos. A acroleína foi encontrada na faixa de 6,4 a 9,3 ppbv nos ambientes internos estudados. Na área externa, entretanto, foram encontrados valores similares (6,4 e 6,8 ppbv) aos dos ambientes internos obtendo razões I/E próximas de 1. Os compostos podem ter sido emitidos por materiais de construção e acabamento, fumaça do tabaco, adesivos, via metabolismo microbiano e bacteriano ou podem ter sido transportados por correntes de ar do ambiente externo para o ambiente interno / The quantification of 11 carbonyl compounds (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, crotonaldehyde, butiraldehyde, benzaldehyde, isovaleraldehyde, valeraldehyde and 2,5-dimethylbenzaldehyde) and the identification of another 43 volatile organic compounds (alkanes, alkenes, aromatic, halogenated and nitrogenated compounds) have been done with samples of 9 different indoor places inside the University Hospital at USP in São Paulo. Among the carbonyl compounds, there where found higher quantities of formaldehyde, acetone, acetaldehyde and acrolein in this order. The highest ratios of formaldehyde mixture have been observed at the Macroscopic room (169.88 and 90.2 ppbv) and Histological Techniques (11.7 and 58.7 ppbv), due to the routine activities of these places. At the Macroscopy room, the level of formaldehyde identified (100 ppbv) was above the international limits established to non-industrial internal places. The ratios of the mixture of indoor and outdoor places, I/O, indicate the biggest presence of carbonyl compounds in internal places. Acrolein has been identified (6.4 to 9.3 ppbv) at indoor places. At the external area, there where found similar values (6,4 to 6,8 ppbv), and the ratio I/O obtained is near to 1. The origin of these compounds is possibly construction materials, smoke of cigarettes, adhesives, metabolism of microorganisms or they may have come from the outdoor to the indoor

No presente trabalho, métodos analíticos empregando a eletroforese capilar com detecção condutométrica sem contato CE - C4D foram desenvolvidos para a determinação de diversas espécies no biodiesel e etanol combustível. A concentração das espécies inorgânicas (Na+, K+, Ca2+, Mg2+, SO4 2- e PO4 3-) e glicerol no biodiesel são de interesse das agências reguladoras devido à capacidade dessas espécies em formar compostos indesejáveis no motor. A separação dos cátions foi realizada utilizando eletrólito de corrida (BGE) contendo 30 mmol L-1 de Ácido 2-N-morfolino-etanosulfônico (MES) / L-histidina, pH 6. A separação das espécies aniônicas foi realizada em BGE semelhante contendo 0,2 mmol L-1 brometo de cetiltrimetilamônio. Para a determinação do glicerol, que é uma espécie neutra, foi empregada uma etapa de oxidação utilizando periodato. Esta reação é específica para polióis e tem como um dos produtos o iodato. A quantidade de iodato produzida pela reação foi determinada por CE. A separação foi realizada em aproximadamente 1 min, utilizando BGE contendo 30 mmol L-1 de ácido acético, pH 3. Este trabalho também apresenta estudos sobre a formação de ácidos orgânicos de baixo PM durante a etapa de auto-oxidação do biodiesel, uma vez que esta etapa acarreta no aumento da viscosidade e acidez, ocasionando a formação de gomas e sedimentos e, conseqüentemente, o entupimento de filtros de combustíveis. As amostras foram oxidadas utilizando equipamento para teste de oxidação acelerada (Método Rancimat) e CE - C4D foi utilizada para a análise dos produtos iônicos formados. As principais espécies ácidas encontradas foram os ácidos acético e fórmico. Porém, outras espécies são formadas durante esta etapa, tais como os ácidos acrílico, glicólico, glioxílico, láctico e propiônico. Em particular, o ácido glicólico se mostrou uma espécie de grande importância prática, atuando como um marcador do estágio de oxidação do biodiesel, uma vez que este ácido somente é formado após o desencadeamento da auto-oxidação e, além do mais, esta espécie foi observada em amostras de biodiesel de diferentes origens (algodão, soja, palma e sebo bovido). Adicionalmente, métodos para a determinação de Cl-, SO4 2-, formiato, acetato, formaldeído e acetaldeído em etanol combustível são descritos. A separação foi realizada em BGE contendo 20 mmol L-1 de MES / L-histidina e 0,1 mmol L-1 hidróxido de cetiltrimetilamônio, pH 6. Para a separação dos aldeídos por CE, foi realizada a derivatização com bissulfito. O presente trabalho também apresenta um método alternativo para a determinação do teor de água e de álcool em amostras de etanol combustível. A estratégia descrita é baseada na formação de monoalquil carbonatos (MAC) produzidos pela reação de um álcool e o bicarbonato em meio aquoso. / In this work, methods employing capillary electrophoresis with capacitively coupled contactless conductivity detection (CE - C4D) are introduced for the determination of several species in biodiesel and ethanol fuel. The concentrations of inorganic species (Na+, K+, Ca2+, Mg2+, SO4 2-, and PO43-) and glycerol are of interest for the regulatory authorities due to their ability to form undesirable compounds in the engines. The separation of the cations was done in BGE composed of 30 mmol L-1 of 2-N-morpholino-ethanesulfonic acid (MES)/L-histidine, pH 6. The separation of anionic species was carried out in similar BGE including cetyltrimethylammonium bromide (0.2 mmol L-1). For glycerol, a neutral species, its oxidation with periodate was employed. This well-known reaction is specific to polyols and generates iodate. The amount of iodate produced by the reaction was determined by CE. The separation was carried out in ca. 1 min using BGE composed of 30 mmol L-1 of acetic acid, pH 3. This work also presents studies on the formation of low molecular organic acids during the biodiesel autoxidation step. Since the implications of the biodiesel oxidation are the increased viscosity and acidity, causing formation of insoluble gums and sediments that induce the clogging of the fuel filters. The samples were oxidized using equipment for accelerated oxidation test (Rancimat Method) and CE-C4D was used to analyze the ionic products. The main acid species were acetic and formic acids. However, acrylic, glyoxylic, glycolic, lactic, and propionic acids were also observed only after the oxidation step. Thus, these species are candidates for quality markers for biodiesel. In particular, glycolic acid seems to be a good marker, because it is produced only after auto-oxidation started. Moreover, it was found out in biodiesel of different origins (cotton, soy, palm, and animal fat). In addition, alternative methods to determination of Cl-, SO42-, formate, acetate, formaldehyde and acetaldehyde in ethanol fuel are described. The separation was done in BGE composed of 20 mmol L-1 of MES / L-histidine, and 0.1 mmol L-1 cetyltrimethylammonium hydroxide, pH 6. For aldehydes, a neutral species, a derivatization step with bisulfite was employed. The present work also shows an alternative method for analysis of alcohol and water percentage in fuel samples employing CE - C4D in order to achieve the limits established by regulatory authorities. The strategy is based on the formation of monoalkyl carbonates (MAC) produced by the reaction of an alcohol and bicarbonate in aqueous medium.

Le SO2 est un additif utilisé en oenologie pour ses propriétés antiseptiques,antioxydantes et antioxydasiques. Il est introduit dans les vins en grandes quantités en raisonde son fort pouvoir de combinaison avec les dérivés carbonylés, ce qui limite son activité. Leproblème est que les teneurs maximales de SO2 autorisées ne permettent pas toujours uneprotection suffisante du vin contre les phénomènes de refermentation. L'objectif principal dece projet était de réduire la concentration en dioxyde de soufre dans les vins en éliminant unepartie des dérivés carbonylés responsables de la combinaison bisulfitique. La méthoderetenue a été l’extraction sur phase solide (SPE). Elle fait intervenir des interactions entre unephase liquide et un support solide poreux modifié avec une fonction extractive. Les travauxantérieurs ont permis de sélectionner l’hydrazine et la sulfonylhydrazine comme agentsd’extraction. Ces fonctions ont été fixées sur des supports polymères organiques selon deuxvoies : la fonctionnalisation de résines sulfoniques commerciales et la copolymérisation ensuspension de méthacrylate de glycidyle suivie d’une fonctionnalisation. Les supports solidesobtenus ont été caractérisés afin de valider la fonctionnalisation. Ils ont ensuite été testés surdes solutions modèles du vin et le procédé a prouvé son efficacité. La présence decontaminants dans les solutions a été recherchée avant d’appliquer la méthode sur du vin. / SO2 is an additive used in enology for its antiseptic, antioxidant and antioxydasic properties. It is introduced in wines in large quantities due to its high binding power with carbonyl compounds, which limits its activity. The maximum SO2 content authorized is notalways enough to avoid fermentative phenomena during wine storage. The main objective of this project was to develop a method to reduce the sulfur dioxide concentration in wines byeliminating some of carbonyl compounds responsible for the SO2 binding. The method used was solid-phase extraction (SPE). It involves interactions between a liquid and a porous solid support modified with an extractive function. Previous work allowed to select hydrazine andsulfonylhydrazine as extractive reagents. These functions were fixed on organic polymersupports according to two routes : functionnalization of commercial sulfonic resins and suspension copolymerization of glycidyl methacrylate (followed by the functionnalization). The solid supports obtained were characterized in order to validate the functionnalization.Then selective extractions were executed on model solutions. The diminution of carbonylcompounds concentration and SO2 content was showed by those experiments. The presence of contaminants in the solutions was investigated before applying the method to wine.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-07-27T23:03:07Z No. of bitstreams: 1 Disserta??o - Iv?n Sergio Col?s Gonzalez.pdf: 1019601 bytes, checksum: a974e9e520faa565d9469e1ff902ceed (MD5) / Made available in DSpace on 2015-07-27T23:03:07Z (GMT). No. of bitstreams: 1 Disserta??o - Iv?n Sergio Col?s Gonzalez.pdf: 1019601 bytes, checksum: a974e9e520faa565d9469e1ff902ceed (MD5) Previous issue date: 2013-09-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / In this work was investigated the biocatalytic action of fungus Periconia hispidula to perform reduction reactions of aromatic prochiral carbonyl compounds. Firstly, the influence of the reaction parameters (medium, time, amount of substrate, forms to use the biocatalyst) over the conversion rate and enantiomeric excess in the reduction of acetophenone was investigated. After the determination of the growth curve, the incubation time prior to addition of substrate, was evaluated (4 and 7 days). For 4 days of preincubation time, the best conversion rate to obtain the (S)-1-phenylethanol with e.e of 98% were achieved. Two types of biocatalysts were evaluated: growing cells and resting cells. The best results were obtained with growing cells. By comparing the results obtained from potato-dextrose (BD) culture medium and potato-dextrose (BD) supplemented with Fe 2+, BD medium supplemented with Fe 2+ (0.02 g / L) was selected. The influence of the amount of acetophenone (20 to 200 ?L) was also examined to evaluate the toxicity of the substrate. Quantities of the substrate higher than 100 ?L (0.1%) decreased also conversion rate but the enantiomeric excess. The applicability of this biocatalyst was also evaluated to reduce acetophenone derivates compounds such as 2, 3 and 4-nitroacetophenone, 2, 3 and 4-methylacetophenone? 2, 3 and 4-methoxyacetophenone, 2, 3 and 4-bromoacetophenone, 2, 3 and 4-fluoracetophenone, 2, 4-dimethylacetophenone, 2, 5-dimethylacetophenone? 4-ethylacetophenone, octanophenone, 1-indanone and 2-indanone. Chiral alcohols were obtained with conversion rates from 8% upto higher than 99% and the enantiomeric excess between 54% up to 100%, indicating that the fungus Periconia hispidula is a promising estereoselctive biocatalyst for use in processes for reducing carbonyl compounds. / Neste trabalho foi investigada a a??o biocatal?tica do fungo Periconia hispidula em rea??es de redu??o de compostos carbon?licos arom?ticos pr?-quirais. A influ?ncia de par?metros reacionais (meio, tempo, quantidade de substrato, forma de utiliza??o do biocatalisador) na convers?o e enantioseletividade da redu??o de acetofenona foi inicialmente avaliada. A partir da curva de crescimento, determinou-se o tempo de incuba??o pr?vio a adi??o de substrato (4 e 7 dias). Os melhores resultados de convers?o para a obten??o do (S)-1-feniletanol, com excesso enantiom?rico (e.e) de 98% foram atingidos ap?s quatro dias de incuba??o pr?via do micro-organismo. Duas formas de utiliza??o do biocatalisador foram avaliadas: c?lulas em crescimento e c?lulas em repouso. Os melhores resultados de convers?o foram obtidos com as c?lulas em crescimento. Pela compara??o entre meios de cultura batata-dextrose (BD) e batata-dextrose (BD) suplementado com Fe2+) selecionou-se o meio BD suplementado com Fe2+ (0,02 g/L). A influ?ncia da quantidade de acetofenona (entre 20 ?L e 200 ?L) tamb?m foi analisada com o objetivo de avaliar a toxicidade do substrato. Verificou-se que quantidades de substrato maiores a 100 uL (0,1%) levaram a queda da convers?o e da enantioseletividade. O biocatalisador tamb?m foi testado frente a 23 cetonas pr?-quirais: 2, 3 e 4-nitroacetofenona; 2, 3 e 4-metilacetofenona; 2, 3 e 4-metoxiacetofenona; 2, 3 e 4-bromoacetofenona; 2, 3 e 4-fluoracetofenona; 2,4-dimetilacetofenona; 2,5-dimetilacetofenona; 4-etilacetofenona, octanofenona, 1?indanona e 2-indanona. As convers?es dos alco?is quirais oscilaram entre 8% e 100% com excessos enantiom?ricos de 54 at? mais de 99%, demonstrando que o fungo Periconia hispidula ? um biocatalisador estereosseletivo promissor para aplica??o em processos de redu??o de compostos carbon?licos.

Les biocarburants présentent une alternative prometteuse à l’utilisation de carburants fossiles. Cependant, l’augmentation de la quantité de biocarburants introduite dans les carburants nécessite de connaître leur impact sur les émissions de polluants. Le travail réalisé lors de cette thèse peut être décrit en deux parties : La première traite de l’évaluation des émissions de polluants réglementés et non réglementés émis par la combustion de biocarburants dans un moteur diesel. Différents biocarburants ont été testés : des esters méthyliques d’huile de soja et de colza, des esters éthyliques d’huile usagée et un carburant de référence exempt de tout biocarburant. Les résultats montrent que la nature des biocarburants ainsi que leur teneur ont un impact sur les polluants émis. Par exemple, une diminution de la taille des particules émises a été observée avec l’utilisation des esters méthyliques d’huile de soja. Le deuxième objectif de cette thèse concerne le piégeage des polluants Diesel, notamment des composés organiques volatils par des zéolithes. Plusieurs zéolithes ont été synthétisées puis caractérisées. Des tests d’adsorption par thermogravimétrie ont ensuite été réalisés au laboratoire avec différentes molécules sondes représentatives des polluants émis par les moteurs Diesel (le n-hexane, le p-xylène et l’acétone). Certaines zéolithes comme les zéolithes faujasite présentent des capacités d’adsorption intéressantes. Toutefois, la plupart des résultats montrent une diminution de la capacité d’adsorption avec l’augmentation de la température. Ces zéolithes ont ensuite été placées en sortie d’échappement d’un moteur diesel afin d’étudier leur capacité d’adsorption. / Nowadays, biofuels are a promising alternative to the use of fossil fuels. However, increasing the amount of biofuels introduced in fuels requires to know their impact on emissions pollutants.The work done in this thesis can be described in two parts: The first one deals with the evaluation of emissions of regulated pollutants (NOx, CO, CO2, O2, THC) and unregulated pollutants (volatile organic compounds, carbonyl compounds and fine particles (between 30 nm and 10 microns)) emitted by the combustion of biofuels in a diesel engine. Different biofuels have been tested: methyl esters of soybean oil and rapeseed oil, ethyl esters of used oil and a reference fuel free of biofuel. The results show that the nature of biofuels and their content have an impact on the pollutants emitted. For example, a decrease in the size of the particles emitted was observed with the use of methyl esters of soybean oil. The second objective of this thesis was to trap pollutants, like volatile organic compounds (VOCs) with zeolites. Several hydrophilic and hydrophobic zeolites have been synthesized and characterized. Adsorption tests were then carried by thermogravimetry with different probe molecules representative of pollutants from diesel engines (n-hexane, p-xylene and acetone). Some zeolites such as faujasite zeolites have interesting adsorption capacities. However, most of the results show a decrease in the adsorption capacity with the increase of the temperature. Then, these zeolites have been placed in the exhaust outlet of a diesel engine in order to study their adsorption capacity.

As modern life develops, humans spend most of their time inside buildings. Understanding the effects of different building materials that exist indoors on indoor air quality is crucial to ensure comfort, health, and productivity of building occupants. Indoor air quality (IAQ) is an important field of building science that focuses on studying the existence of different compounds indoors. These compounds include: airborne particles such as dust, volatile organic compounds (VOCs) such as carbonyls, reactive gases such as radon, ozone and others. Ozone is a strong oxidant gas that has adverse effects on human health, and is highly reactive with building materials that exist indoors. This reaction may reduce its concentration indoors, but may produce other by-products that could be more harmful for human health than ozone itself. In this dissertation, ozone reaction with different building materials is investigated in four studies. The first includes studying the effect of indoor carpet fiber type on ozone removal and carbonyl emissions. This study provides valuable data and knowledge about the importance of selecting carpet type and its effect on indoor environment. In the second study, different indoor plants were tested to evaluate their ability to remove ozone. The results from this study show wide variation between plants tested on ozone removal. Also, the ability of plants as ozone removal agent changes as light levels change. The third part studies ozone removal efficiency of HVAC filters previously installed in air handling units located on green and white membrane roofs of a commercial building. Detailed filter surface analysis using scanning electron microscope (SEM) was performed to understand the nature of deposits on these filters. The reason for differences in ozone removal efficiency of two filters in comparison with new filter is also discussed. The fourth study investigated ozone removal and carbonyl emissions from three different VOC content indoor latex paints. The outcomes from this research show that zero VOC latex paint has the most ozone effective removal capacity and this paint is the least carbonyl emitter. The research presented in this dissertation adds new data, valuable knowledge, and expands the understanding of the importance of selecting indoor materials to raise indoor air quality and make the buildings' indoor environment healthier and safer.

The thesis entitled “Design and Development of Metal-Free Cross Dehydrogenative Coupling Reactions for the construction of C-S, C-O and C-C bonds” is divided into three Chapters. Chapter 1 is presented in five parts, which reveals the cross dehydrogenative coupling (CDC) strategies for the C–S bond forming reactions through C–H functionalization strategy using heterocyclic thiols and thiones. Chapter 2 presents tetrabutyl ammonium iodide (TBAI) catalyzed chemoselective α-aminoxylation of ketones with N-hydroxyimidates using TBHP as oxidant under cross dehydrogenative coupling (CDC) strategy. Chapter 3 describes a transition metal-free Minisci reaction for the acylation of isoquinolines, quinolines, and quinoxaline. Chapter 1 Iodine Promoted C-S Bond Forming Reactions using Dimethyl Sulfoxide as an Oxidant Chapter 1 reveals the utility of cross dehydrogenative coupling (CDC) reactions for the formation of C–S bonds by employing C–H functionalization strategies.1 The direct functionalization of C–H bonds to form C–C and C–X (N, O, S and P) bonds using metal-free reaction conditions is an interesting research topic in recent years.2 Use of dimethyl sulfoxide as an oxidant is emerging as one of the research topics of great interest and utility.3 Heterocyclic thiols and thiones are important precursors for synthesizing a variety of pharmaceuticals and biologically active compounds.4 Therefore it is useful to develop CDC reactions using heterocyclic thiols and thiones as precursors. In this chapter, we describe CDC reactions of heterocyclic thiols and thiones for the sulfenylation of ketones, aldehydes, α, β unsaturated methyl ketone derivatives, pyrazolones, enaminones and imidazoheterocycles using DMSO as an oxidant Chapter 1: Part 1 Iodine Promoted Regioselective α-Sulfenylation of Carbonyl Compounds using Dimethyl Sulfoxide as an Oxidant: In this chapter, a rare regioselective C–H sulfenylation of carbonyl compounds with heterocyclic thiones and thiols have been described using iodine and dimethyl sulfoxide as reagents. Thus, dimethyl sulfoxide (as an oxidant) and stoichiometric amount of iodine have been used for the sulfenylation of ketones using heterocyclic thiones. Whereas the sulfenylation of ketones with heterocyclic thiols required catalytic amount of iodine. This protocol offers a rare regioselective sulfenylation of (i) methyl ketones in the presence of more reactive α-CH2 or α-CH groups, and (ii) aldehydes under CDC method. A few representative examples are highlighted in Scheme 1.5 The application of this methodology has been demonstrated by synthesizing a few precursors for Julia-Kocienski olefination intermediates. Scheme 1. Iodine promoted rare regioselective α-sulfenylation of ketones and aldehydes Siddaraj , Y.; Prabhu, K. R. Org. Lett. 2016, 18, 6090 Chapter 1: Part 2 Regioselective Sulfenylation of α’-CH3 or α’-CH2 Groups of α, β Unsaturated Ketones using Dimethyl Sulfoxide as an Oxidant: In this chapter, an interesting regioselective sulfenylation of α’-CH3 or α’-CH2 groups of α, β unsaturated ketones using dimethyl sulfoxide as an oxidant and catalytic amount of aq. HI (20 mol %) as an additive has been described. This eco-friendly method uses readily available, inexpensive I2 or HI and DMSO. This methodology exhibits a high regioselectivity without forming Michael addition product in the presence of strong acid such as aq. HI or iodine, which is difficult to achieve under cross dehydrogenative coupling (CDC) conditions. Current methodology exhibits a broad substrate scope. A few examples are shown in Scheme 2.6 Scheme 2. HI and DMSO promoted α’-sulfenylation of α, β unsaturated ketones Siddaraju, Y.; Prabhu, K. R. (Manuscript submitted) Chapter 1: Part 3 Iodine Catalyzed Sulfenylation of Pyrazolones using Dimethyl Sulfoxide as an Oxidant: In this chapter, a sustainable and efficient strategy for the sulfenylation of pyrazolones has been described using metal-free conditions by employing DMSO as an oxidant and iodine as a catalyst. A variety of heterocyclic thiols, heterocyclic thiones and disulfides undergo C–H functionalization reaction with pyrazolone derivatives furnishing the corresponding sulfenylated products in short time. Most of the products are isolated in pure form without column purification. A few examples are presented in Scheme 3.7 Scheme 3. Iodine promoted sulfenylation of pyrazolones Siddaraju, Y.; Prabhu, K. R. Org. Biomol. Chem. 2017, 15, 5191 Chapter 1: Part 4 Iodine-Catalyzed Cross Dehydrogenative Coupling Reaction: Sulfenylation of Enaminones using Dimethyl Sulfoxide as an Oxidant: In this chapter, synthesis of poly functionalized aminothioalkenes has been described using substoichiometric amount of iodine and DMSO as an oxidant. This metal-free methodology enables a facile sulfenylation of enaminones with heterocyclic thiols and thiones. This methodology is one of the simple approaches for the sulfenylation of enaminones under cross dehydrogenative coupling method. A few examples are highlighted in Scheme 4.8 Scheme 4. Cross-dehydrogenative coupling approach for sulfenylation of enaminones Siddaraju, Y.; Prabhu, K. R. J. Org. Chem. 2017, 82, 3084 Chapter 1: Part 5 Iodine-Catalyzed Cross Dehydrogenative Coupling Reaction: A Regioselective Sulfenylation of Imidazoheterocycles using DMSO as an Oxidant: In this chapter, a simple synthetic approach for the regioselective sulfenylation of imidazoheterocycles using iodine as a catalyst and DMSO as an oxidant under cross dehydrogenative coupling (CDC) reaction conditions has been demonstrated. This protocol provides an efficient, mild and inexpensive method for coupling heterocyclic thiols and heterocyclic thiones with imidazoheterocycles. This is the first report on sulfenylation of imidazoheterocycles with heterocyclic thiols and heterocyclic thiones under metal-free conditions. A few examples are shown in Scheme 5.9 Scheme 5. Cross-dehydrogenative coupling approach for sulfenylation of imidazoheterocycles Siddaraju, Y.; Prabhu, K. R. J. Org. Chem. 2016, 81, 7838 Chapter 2 Chemoselective α-Aminoxylation of Aryl Ketones: Cross Dehydrogenative Coupling Reactions Catalyzed by Tetrabutyl Ammonium Iodide: In this chapter, chemoselective α-aminoxylation of ketones with N-hydroxyimidates catalyzed by tetrabutyl ammonium iodide (TBAI) has been presented. The coupling reaction of a variety of ketones with N-hydroxysuccinimide (NHSI), N-hydroxyphthalimide (NHPI), N-hydroxybenzotriazole (HOBt) or 1-hydroxy-7-azabenzotriazole (HOAt) using TBHP as oxidant has been investigated. This α-aminoxylation of ketones is chemoselective as aryl methyl ketones, aliphatic ketones as well as benzylic position are inactive under the reaction condition. A few examples are highlighted in Scheme 6.10 The application of this method has been demonstrated by transforming a few coupled products into synthetically useful vinyl phosphates. Scheme 6. Chemoselective α-aminoxylation of ketones with N-hydroxyimidates Siddaraju, Y.; Prabhu, K. R. Org. Biomol. Chem. 2015, 13, 11651 Chapter 3 A Transition Metal-Free Minisci Reaction: Acylation of Isoquinolines, Quinolines, and Quinoxaline: In this chapter, transition metal-free acylation of isoquinoline, quinoline and quinoxaline derivatives with aldehydes has been described by employing TBAB (tetrabutyl ammonium bromide, 30 mol %) and K2S2O8 as an oxidant under cross dehydrogenative coupling (CDC) reaction. This intermolecular acylation of electron-deficient heteroarenes provides an easy access and a novel acylation method of heterocyclic compounds. The application of this CDC strategy has been illustrated by synthesizing isoquinoline-derived natural products. A few representative examples are shown in Scheme 7.11 Scheme 7. CDC reactions of heteroarenes with aldehydes Siddaraju, Y.; Lamani, M.; Prabhu, K. R. J. Org. Chem. 2014, 79, 3856

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Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2013-04-23T14:07:51Z No. of bitstreams: 1 Thalita Silva.pdf: 824830 bytes, checksum: 144a9fb3d8d0b2ef49b28207c4f7d487 (MD5) / Made available in DSpace on 2013-04-23T14:07:52Z (GMT). No. of bitstreams: 1 Thalita Silva.pdf: 824830 bytes, checksum: 144a9fb3d8d0b2ef49b28207c4f7d487 (MD5) Previous issue date: 2007 / O consumo de frituras é significativo no hábito dos brasileiros e tem aumentado nos últimos anos, isto por ser este um método rápido de preparação e por conferir características agradáveis de aroma e sabor aos alimentos fritos. Durante o processo de fritura, os óleos vegetais são continuamente ou repetidamente expostos a temperaturas elevadas, na presença de oxigênio atmosférico, levando os mesmos à degradação por diferentes tipos de reação. Alguns dos produtos de degradação formados, como por exemplo compostos carbonílicos, como formaldeído, acetaldeído e acroleína, podem ter efeitos adversos sobre a saúde humana. Neste trabalho determinou-se as taxas de emissão de compostos carbonílicos (CC), produzidos por óleos de dendê e soja quando submetidos a aquecimento a 180°C e exposição ao ar por diferentes intervalos de tempo, em processos contínuo e descontínuo e diferentes razões superfície:volume (S/V). Os CC foram coletados e derivatizados em cartuchos de sílica funcionalizados com C18 e impregnados com solução ácida de 2,4-DNPH, sendo a seguir extraídos e analisados por CLAE-DAD e, em alguns casos, CLAE-EM com ionização por eletrospray. Dentre os CC identificados nas emissões, destacaram - se no óleo de dendê, formaldeído; acetaldeído; acroleína; propanal; butanal; pentanal; hexanal; (E)-2-heptenal; heptanal; (E)-2-octenal; octanal; nonanal e (E)-2-decenal, enquanto no óleo de soja destacaram-se formaldeído; acetaldeído; acroleína; hexanal e (E)-2-heptenal. Dentre os quantificados, o que apresentou as maiores taxas de emissão nos dois óleos, nas três relações S/V estudadas, foi a acroleína, emitida em maiores taxas pelo óleo de soja. Em seguida, vieram o hexanal e o (E)-2- heptenal. No estudo da influência da relação S/V, as taxas de emissão estiveram, em geral, diretamente relacionadas à razão superfície/volume de óleo utilizado, embora CC saturados e insaturados tenham se comportado de maneira diferente frente à oxidação. Durante aquecimento descontínuo, houve uma tendência ao aumento nas taxas de emissão, ao longo do tempo, para os aldeídos saturados. Aldeídos insaturados, ao contrário, tiveram uma diminuição ao longo do tempo, devida provavelmente à alta reatividade da dupla ligação presente nestes compostos. Outros compostos orgânicos voláteis (COV) foram avaliados qualitativamente por extração do headspace e análise por CGAR-EM. As principais classes de compostos identificadas foram, mais uma vez, aldeídos alifáticos saturados e insaturados, embora também álcoois insaturados, ácidos carboxílicos e o 2-pentil-furano, todos provenientes de degradação lipídica. Finalmente, esse estudo mostra que a relação superfície/volume, o tempo de fritura, a forma de aquecimento (contínua ou descontínua), o tipo de óleo utilizado e a presença ou não de antioxidantes são fatores importantes na degradação dos óleos vegetais. Vale ressaltar que embora as emissões de acroleína e de outros aldeídos possam ser elevadas mesmo após períodos curtos de aquecimento do óleo, isso não corresponde necessariamente à altas exposições pelos trabalhadores em cozinha, uma vez que essas vão ser afetadas por outros fatores, tais como o grau de ventilação/exaustão do ar no ambiente. Todavia, elas podem servir como alerta para ações de prevenção. / Salvador