Cyclitols are of great importance due to their biological activities playing a crucial role in living organisms as well as their synthetic usefulness in the synthesis of other natural compounds or pharmaceuticals. In this study, new synthetic strategies leading to the aminocyclitols were investigated. The synthesis of aminoconduritol and aminoinositol derivatives (173 and 174) were achieved starting from easily available compound, 7-oxa-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (166) obtained from the Diels-Alder reaction of furan and maleic anhydride. The anhydride functionality in 166 was converted into the half-ester 169 by desymmetrization in methanol. The carboxylic acid moiety in the molecule was used to obtain urethane functionality by making use of Curtius rearrangement. After the cleavage of oxa-bridge with the help of a Lewis acid the aminoconduritol derivative 173 was synthesized. The cis-dihydroxylation of 173 with osmium tetroxide resulted in the formation of inositol derivative 174. Consequently, we developed a new methodology for the synthesis of aminocyclitol derivatives.

Poly (co iso-butyl vinyl ether-alt-maleic anhydride), an alternating copolymer, was synthesised. For this class of copolymers the formation of an electron-donor complex is invoked to explain their microstructure in which the two comonomers strictly alternate. Due to its polarity, this copolymer constitutes a potential additive for imparting hydrophilic properties to a hydrophobic matrix. In order to obtain narrow molecular weight polymers and study the relation between the molecular weight of this additive and its ability to migrate to the host polymer surface, chain transfer agents were introduced in the system and also the Reversible Addition-Fragmentation chain Transfer (RAFT) process was employed. Free radical polymerisation was first carried out to allow for a comparison with the RAFT process and kinetics of copolymerisation was studied by NIR-FTIR and 1H NMR spectroscopy in order to analyse the rate of reaction of each comonomer. Dibenzyl trithiobenzoate, 3-benzyl sulfanyl thiocarbonyl sulfanyl-propionic acid and dibenzyl trithiobenzoate were used as RAFT agents. Results demonstrate that only benzyl dithiobenzoate is able to control the molecular weight of this copolymer and decrease its polydispersity index; possible reasons laying behind this result are discussed. It was also found that, in particular in the presence of benzyl dithiobenzoate, poly(iso-butyl vinyl ether) forms. This is an unusual phenomenon considering that the free radical polymerisation affords alternating copolymers and that iso-butyl vinyl ether is a monomer that polymerises through the cationic process. Experiments were carried out in various solvents in an attempt to counteract this side reaction, but no appreciable correlation between the properties of the solvents and the formation of homopolymer were found. Various hypothesis are considered, however it is likely that, in the conditions adopted, the presence of the RAFT agents alters the equilibrium constant of complex formation favouring the synthesis of the homopolymer. In addition to this side???reaction also inhibition of the copolymerisation reaction was at times encountered and an investigation into this phenomenon was also conducted.

Thesis--Paris, 1948. / Includes bibliographical references (p. [177]-183).

Techn. Hochsch., Diss., 2002--Aachen.

Made available in DSpace on 2014-06-11T19:30:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-10-22Bitstream added on 2014-06-13T21:01:07Z : No. of bitstreams: 1 maciel_cdg_dr_botfca.pdf: 4558359 bytes, checksum: 0776cfa53f6d57830969703b5def9fbf (MD5) / O presente trabalho teve como objetivo analisar a viabilidade de uso do anidrido naftálico (NA) no tratamento de sementes de espécies gramíneas, assim como no tratamento de toletes de Saccharum spp, contra os efeitos causados por herbicidas inibidores da síntese de carotenóides. O trabalho foi constituído de quatro etapas, sendo as etapas 1 e 3 conduzidas a campo e em casa de vegetação no NUPAM/FCA/UNESP, Botucatu-SP, e as etapas 2 e 4, em estufa plástica e a campo na ESAPP e Empresa Guacho S/A, Paraguaçu Paulista-SP. Nas etapas 1, 2 e 3, de forma geral, foi estudado para as espécies Sorghum bicolor; Penisetum americanum, Panicum maximum, Brachiaria brizantha e Zea mays o efeito da combinação ou não do tratamento de sementes com NA submetidas ao uso dos herbicidas isoxaflutole (IFT) e clomazone, utilizando-se diferentes dosagens, tipos de solos e formas de aplicação. Na etapa 4 foi estudada a combinação de NA no tratamento de toletes da variedade SP 813250 (testemunhas sem NA; aplicação por imersão em solução de 3,0 g L-1 por duas horas; pulverização de 25 g ha-1 de NA sobre os colmos) e herbicida (testemunha; 112 g ha-1 de isoxaflutole; 1440 g ha-1 de metribuzin), e mais um tratamento adicional, onde os toletes foram imersos apenas em água sem adição de NA. O uso de NA (0,50% de p/p) no tratamento de sementes reduziu a intoxicação do híbrido Colorado 32 contra a ação do isoxaflutole, em pré-emergência da cultura, assim como favoreceu o aumento da produtividade dos híbridos Cargill 435 e Colorado 32, na ausência ou presença do efeito herbicida. O tratamento de sementes com NA (0,50% de p/p) protegeu a espécie S. bicolor BR 304 contra os sintomas visuais de intoxicação do isoxaflutole (112 g ha-1) e clomazone (1000 g ha-1)... / The present work had as objective to analyze the viability of naphthalic anhydride (NA) use in grass crops, through seed treatment, as well as in stalks treatment of Saccharum spp, against the effects caused by carotenoid synthesis inhibitor herbicides. The work was constituted by four step, being the 1st and 3rd ones carried out in field conditions and glasshouse at the NUPAM/FCA/UNESP, Botucatu - São Paulo State; 2nd and 4th step were conducted in plastic greenhouse and field at the ESAPP and Guacho S/A, Paraguaçu Paulista - São Paulo State. In a general way, 1st, 2nd and 3rd step was studied Sorghum bicolor; Penisetum americanum, Panicum maximum; Brachiaria brizantha and Zea mays L. species in the combination with the effect or not of seed treatment with NA submitted to the isoxaflutole and clomazone, being used different doses, kinds of soils and application forms. In 4th step, treatments included the combination of three conditions of NA stalk treatment, SP 813250 variety (check without NA; application by immersion in solution of 3,0 g L-1 of NA for two hours; spraying of 25 g ha-1 of NA over the stalks) and three herbicide conditions (check without herbicide; 112 g ha-1 at isoxaflutole; 1440 g ha-1 at metribuzin), and an additional treatment, where the stalks were just put inside water without NA. Seed treatment with NA (0,50% of w/w) reduced Colorado 32 hybrid intoxication by isoxaflutole action in preemergence of the crop, as well as favored the increase of Cargill 435 and Colorado 32 hybrids yield, in the absence or presence of herbicide effect. Seed treatment with NA (0,50% of p/p) protected S. bicolor BR 307 against the visual isoxaflutole (112 g ha-1) and clomazone (1000 g ha-1... (Complete abstract, click electronic address below)

The thesis describes the synthesis and application of various alkynones derived from the bis-Weinreb amide of tartaric acid in the total synthesis of macrolactone natural products. The thesis is divided into three sections. First section of the thesis describes the optimization and generalization of the procedure for the addition of alkynyl Grignard / lithium reagents to the bis-Weinreb amide derived from tartaric acid to yield the mono alkynyl ketones was developed. Application of the formed γ-oxo amides was demonstrated in the synthesis of polyols with varied substitutions particularly the synthesis of 1,2,4-triols was accomplished using Ley’s dithianylation as the key step. Scheme 1: Synthesis of polyols from the bis-weinreb amide of tartaric acid. Application of the strategy to the total synthesis of decanolactone natural products achaetolide and (Z)-isomer of (6S,7R,9R)-6,7-dihydroxy-9-propylnon-4-eno-9-lactone was featured. Section B of the thesis deals with the enantiospecific total synthesis of 14-membered macrolactone Sch 725674. Key reactions in the synthesis include the synthesis of the 1,2,4-triol unit from tartaric acid, olefin cross metathesis and ring closing metathesis. Scheme 4: Enantiospecific total synthesis of Sch 725674. Section C of the thesis describes the enantiospecific synthesis of the C9-C22 fragment of the 28-membered polyene polyol macrolide pentamycin. Although isolated in 1958, total synthesis of this antifungal compound was not reported. In application of the methodology developed, the alkynone prepared from the bis-Weinreb amide was elaborated to the required fragment.

Polipropileno (PP) é um termoplástico com ótimo balanço de propriedades, baixo custo e largo espectro de aplicações. Seu uso como material de engenharia é limitado pelos seus valores relativamente baixos de propriedades mecânicas. A adição de reforço ao PP melhora suas propriedades termomecânicas, tornando-o adequado para fabricação de peças de engenharia como composto termoplástico. Fibra de vidro (FV) é o reforço mais empregado em compostos de PP devido a maior resistência mecânica específica gerada no PP e por atuar como agente nucleante. Devido à diferença entre as naturezas das ligações secundárias, há pouca afinidade química entre PP-FV, sendo necessária a modificação interfacial através de agentes de acoplamento poliméricos (AA) para melhorar o desempenho termomecânico deste composto. Averiguou-se neste trabalho a influência de dois AA, um à base de PP e outro à base de EPDM, ambos graftizados com anidrido maleico (PAM e EAM, respectivamente), no comportamento térmico do composto PP∕FV. Os compostos PP30FV-AA foram preparados em extrusora dupla rosca ZSK 26, e posteriormente injetados em uma injetora Airburg para obtenção de corpos de prova utilizando teor fixo de 30% FV e teores de 0,5∕1,0∕2,0% AA. O PP e seus compostos foram caracterizados via microscopia óptica acoplada à placa Hot Stage, cristalização isotérmica e não isotérmica por calorimetria (DSC), resistência à deflexão térmica (HDT), morfologia da fratura (MEV) e comportamento viscoelástico (DMA) para analisar a influência do AA e da FV. Os resultados obtidos foram avaliados estatisticamente via metodologia ANOVA (Analysis of Variance). O efeito sinérgico FV-AA na cristalização isotérmica do PP foi dependente da combinação temperatura-natureza-teor de AA, sendo a temperatura o fator preponderante. A interação interfacial entre a matriz- reforço foi substancialmente favorecida pelo PAM. O uso de EAM retardou a cristalização do PP, enquanto que o PAM favoreceu este processo. Constatou-se que o AA teve pouca influência no tempo de meia-vida de cristalização nas menores isotermas e, para isotermas mais próximas à fusão do PP, o PAM apresentou menores valores deste parâmetro. Os valores de deflexão térmica foram semelhantes para todas as formulações contendo PAM, enquanto que a adição de EAM decresceu esta propriedade. Em temperaturas inferiores à transição vítrea (Tg) do PP, todos os compostos com AA apresentaram menor módulo elástico em relação ao composto puro; em temperaturas superiores à Tg, o PAM favoreceu aumentou esta propriedade na faixa de temperatura em que o composto usualmente é utilizado. / Polypropylene (PP) features by its properties balance, price and large array of applications. However, its use as engineering component is limited by relative low mechanical properties. PP reinforcement improves its thermomechanical properties, turning it into suitable to produce engineering components as a reinforced thermoplastic composite. Glass fiber (GF) is the most usual reinforce utilized in PP due to its great specific mechanical strength elastic modulus and nucleation capability. In reason of different secondary bonds between PP and GF, it is mandatory to modify the interface between these domains through polymeric coupling agents (CA) to improve thermomechanical performance. It was evaluated the influence of two CA based on PP and EPDM grafted with maleic anhydride (PAM and EAM) on thermal behavior of PP∕GF composite. PP30GF-CA composites were prepared in a twin screw extrusor ZSK 26 and injected in an injector Airburg with fixed GF content (30%) and different CA contents (0.5∕1.0∕2.0%). PP and PP composites were analyzed by optical microscopy with Hot Stage, isothermal and non-isothermal crystallization (DSC), as well as viscoelastic behavior. The results were statistically evaluated by ANOVA (Analysis of Variance) methodology. The synergic role between GF∕CA in PP crystallization was dependent on temperature-nature-CA content, mainly influenced by temperature. Interfacial adhesion was mainly favored by PAM. The results pointed a possible PP isotherm crystallization retardant by EAM, whereas PAM significantly favored this same process. CA presence in PP30GF composite did not influence crystallization half-life time values in lower isotherms, while in isotherms near PP melting temperature, PAM considerably decreased this parameter. Deflection thermal values were not affected by PAM, while EAM decreased this property in whole formulations. CA did not improved PP∕GF elastic modulus below PP glass transition (Tg), while in temperatures above Tg, PAM improved PP-GF this same parameter.

Polipropileno (PP) é um termoplástico com ótimo balanço de propriedades, baixo custo e largo espectro de aplicações. Seu uso como material de engenharia é limitado pelos seus valores relativamente baixos de propriedades mecânicas. A adição de reforço ao PP melhora suas propriedades termomecânicas, tornando-o adequado para fabricação de peças de engenharia como composto termoplástico. Fibra de vidro (FV) é o reforço mais empregado em compostos de PP devido a maior resistência mecânica específica gerada no PP e por atuar como agente nucleante. Devido à diferença entre as naturezas das ligações secundárias, há pouca afinidade química entre PP-FV, sendo necessária a modificação interfacial através de agentes de acoplamento poliméricos (AA) para melhorar o desempenho termomecânico deste composto. Averiguou-se neste trabalho a influência de dois AA, um à base de PP e outro à base de EPDM, ambos graftizados com anidrido maleico (PAM e EAM, respectivamente), no comportamento térmico do composto PP∕FV. Os compostos PP30FV-AA foram preparados em extrusora dupla rosca ZSK 26, e posteriormente injetados em uma injetora Airburg para obtenção de corpos de prova utilizando teor fixo de 30% FV e teores de 0,5∕1,0∕2,0% AA. O PP e seus compostos foram caracterizados via microscopia óptica acoplada à placa Hot Stage, cristalização isotérmica e não isotérmica por calorimetria (DSC), resistência à deflexão térmica (HDT), morfologia da fratura (MEV) e comportamento viscoelástico (DMA) para analisar a influência do AA e da FV. Os resultados obtidos foram avaliados estatisticamente via metodologia ANOVA (Analysis of Variance). O efeito sinérgico FV-AA na cristalização isotérmica do PP foi dependente da combinação temperatura-natureza-teor de AA, sendo a temperatura o fator preponderante. A interação interfacial entre a matriz- reforço foi substancialmente favorecida pelo PAM. O uso de EAM retardou a cristalização do PP, enquanto que o PAM favoreceu este processo. Constatou-se que o AA teve pouca influência no tempo de meia-vida de cristalização nas menores isotermas e, para isotermas mais próximas à fusão do PP, o PAM apresentou menores valores deste parâmetro. Os valores de deflexão térmica foram semelhantes para todas as formulações contendo PAM, enquanto que a adição de EAM decresceu esta propriedade. Em temperaturas inferiores à transição vítrea (Tg) do PP, todos os compostos com AA apresentaram menor módulo elástico em relação ao composto puro; em temperaturas superiores à Tg, o PAM favoreceu aumentou esta propriedade na faixa de temperatura em que o composto usualmente é utilizado. / Polypropylene (PP) features by its properties balance, price and large array of applications. However, its use as engineering component is limited by relative low mechanical properties. PP reinforcement improves its thermomechanical properties, turning it into suitable to produce engineering components as a reinforced thermoplastic composite. Glass fiber (GF) is the most usual reinforce utilized in PP due to its great specific mechanical strength elastic modulus and nucleation capability. In reason of different secondary bonds between PP and GF, it is mandatory to modify the interface between these domains through polymeric coupling agents (CA) to improve thermomechanical performance. It was evaluated the influence of two CA based on PP and EPDM grafted with maleic anhydride (PAM and EAM) on thermal behavior of PP∕GF composite. PP30GF-CA composites were prepared in a twin screw extrusor ZSK 26 and injected in an injector Airburg with fixed GF content (30%) and different CA contents (0.5∕1.0∕2.0%). PP and PP composites were analyzed by optical microscopy with Hot Stage, isothermal and non-isothermal crystallization (DSC), as well as viscoelastic behavior. The results were statistically evaluated by ANOVA (Analysis of Variance) methodology. The synergic role between GF∕CA in PP crystallization was dependent on temperature-nature-CA content, mainly influenced by temperature. Interfacial adhesion was mainly favored by PAM. The results pointed a possible PP isotherm crystallization retardant by EAM, whereas PAM significantly favored this same process. CA presence in PP30GF composite did not influence crystallization half-life time values in lower isotherms, while in isotherms near PP melting temperature, PAM considerably decreased this parameter. Deflection thermal values were not affected by PAM, while EAM decreased this property in whole formulations. CA did not improved PP∕GF elastic modulus below PP glass transition (Tg), while in temperatures above Tg, PAM improved PP-GF this same parameter.

Orientador: Carlos Roque Duarte Correia / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T04:40:41Z (GMT). No. of bitstreams: 1 Miranda_KarenFabianeCanto_D.pdf: 2096574 bytes, checksum: b7fd48d07ff428a29ed0b7b0b0c1ad8c (MD5) Previous issue date: 2010 / Resumo: O primeiro capítulo deste trabalho concentra-se no estudo metodológico da reação de Heck com anidrido maleico empregando diversos sais de arenodiazônio. A reação foi investigada em diversas condições e, num primeiro momento, foi possível, utilizando acetato de paládio como catalisador, preparar uma série de anidridos maleicos mono e diarilados através da reação com sais de diazônio contendo grupos doadores de elétrons. Também investigou-se a reação empregando sais de diazônio contendo grupos retiradores de elétrons, entretanto, com o sistema catalítico utilizado inicialmente, não foi possível obter os correspondentes anidridos maleicos substituídos. A utilização do catalisador POPd solucionou o problema do emprego de sais de diazônio contendo grupos retiradores de elétrons. Desse modo foi possível preparar uma série de anidridos maleicos mono e diarilados, com diferentes demandas eletrônicas e padrões de substituição, em rendimentos satisfatórios. Além disso, foi possível preparar também anidridos maleicos dissubstituídos simétricos e não simétricos. Vários dos anidridos maleicos preparados apresentaram fluorescência. O segundo capítulo mostra a aplicabilidade da metodologia desenvolvida. É apresentada a síntese do alcalóide de origem marinha Policitrina A através de uma rota sintética curta, que tem como etapas chaves duas reações de Heck consecutivas com anidrido maleico empregando sal de diazônio. Neste capítulo também são mostrados os esforços visando à síntese total do alcalóide Policitrina B e a síntese formal do mesmo / Abstract: Chapter one of this work deals with methodological studies of the Heck reaction with maleic anhydride using several arenediazonium salts. Several reaction conditions were investigated and at first, it was possible by the use of palladium acetate as catalyst, to prepare a series of mono and diarylated maleic anhydrides through reaction with diazonium salts bearing electron donating groups. The reactions using diazonium salts bearing electron withdrawing groups were also investigated although, with the previous catalytic system used, the correspondent substituted maleic anhydrides weren¿t obtained. The use of POPd catalyst solved the problematic use of diazonium salts bearing electron withdrawing groups. In this way, it was possible to prepare a series of mono and diarylated maleic anhydrides, with different electron demanding conditions and substitution patterns, with satisfactory yields. Besides this, it was possible to prepare symmetric and non-symmetric bi-substituted maleic anhydrides too. Several of this maleic anhydrides prepared displayed fluorescence. Chapter two presents applications of the methodology developed in chapter one. The synthesis of marine alkaloid Polycitrin A is presented through a short synthetic route which has as key steps two consecutive Heck reactions with maleic anhydride using diazonium salt. Efforts towards total synthesis of alkaloid Polycitrin B as well as its formal synthesis are also shown in this chapter / Doutorado / Quimica Organica / Doutor em Ciências

Condensation of 2,3-dichloromaleic anhydride and o-phenylenediamine in refluxing toluene affords the three compounds 2,3-dichloro-N-o-C6H4(NH2)maleimide (1), N,N¢-o-C6H4-bis(2,3-dichloromaleimide) (2), and 2,3-dichloropyrrolo[1,2-a]benzimidazol-1-one (3), with compound 1 as the major product. Repeating the same reaction in the presence of added PTSA furnishes compound 3 as the major product. Treatment of 3 with methylthiol in the presence of pyridine affords monosulfide compounds 2-chloro-3-methylthiopyrrolo[1,2-a]benzimidazol-1-one (4) and and the disulfide derivatives 2,3-di(methylthio)pyrrolo[1,2-a]benzimidazol-1-one (5). The substitution of the first chlorine group in compound 3 occurs regioselectively at C-3 to produce compound 4, followed by replacement of the remaining chlorine group to furnish the disulfide compounds 5. The new compounds 1-5 have been isolated by column chromatography and characterized by IR, NMR, XRD, CV and etc.