The main focus of this thesis has been directed towards preparation and oxidative carbocyclization of en-, dien- and aza-enallenes. In the first part of this thesis, a stereoselective oxidative carbocyclization of dienallenes was realized. By employing cheap and readily available palladium trifluoroacetate we were able to efficiently cyclize a variety of dienallenes into hydroxylated carbocycles in high yield and high selectivity. This oxidative process was compatible with two different reoxidation protocols: one relying on p-benzoquinone (BQ) as the oxidant and the other employing molecular oxygen as the oxidant. In the second part of the thesis the carbocyclization methodology was extended to include carbocyclization of aza-enallenes. This was achieved in two distinct steps. First, a copper-catalyzed coupling of allylic sulfonamides with bromoallenes was developed, giving access to the corresponding aza-enallenes. Subjecting these substrates to catalytic amounts of palladium acetate, along with BQ as the oxidant, rendered N-heterocycles in good yield. The reactivity of these N-heterocycles towards activated dienophiles was later exploited in a tandem (aerobic) oxidative carbocyclization/Diels-Alder reaction. The third topic involves efficient oxidative arylative/borylative carbocyclization of enallenes. These reactions, catalyzed by palladium acetate, relies on transmetallation of a (σ-alkyl)palladium(II) intermediate with diboranes or arylboronic acids. With this novel methodology we were able to obtain an array of arylated or borylated carbocycles, as single diastereomers, in high yield. Finally, we developed a palladium(II)-catalyzed cyclization of allylic carbamates. This mild, operationally simple, and scalable catalytic reaction opens up access to an array of oxazolidinones in high yield and excellent diastereoselectivity. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 6: Manuscript.</p>

The first part of this thesis describes a synthetic strategythat provides all eight possible isomers of a given vic-aminoalcohol starting from vinylepoxides. The value of a generalroute is evident, as several isomers are needed ininvestigations of structure-activity relationships forpharmacologically active derivatives, and for optimizing theperformance of chiral ligands containing the amino alcoholmoiety. Vinylepoxides, obtained in high enantiomeric excess, werering-opened both with inversion and retention ofstereochemistry, delivering two diastereomeric amino alcoholswith high regio- and stereoselectivity. Via ring-closure toaziridines and subsequent regioselective ring-opening withsuitable oxygen nucleophiles, the two remaining amino alcoholswere selectively achieved. Within this study, two efficient protocols for theregioselective and stereospecific aminolysis of vinylepoxideshave been presented. Comparedto previous methods, theseprocedures use milder reaction conditions, shorter reactiontimes, generally give higher yields and are applicable to alarger set of substrates. Furthermore, the ring-closure ofvic-amino alcohols to the corresponding N-H vinylaziridines hasbeen investigated. Three routes have been found useful, whichone is preferred depends on substrate and scale. In the second part of the thesis, the synthetic strategy isapplied on the synthesis of Sphingosine and its regio- andstereoisomers. Moreover, a rapid way of determining relativeconfiguration of vic-amino alcohols is described, which shouldbe of substantial use when amino alcohols are formed bydiastereoselective reactions. amino alcohols, vinylepoxides, vinylaziridines, oxazolines,oxazolidinones, ring-opening, regioselective,diastereoselective, sphingosine, configuration, NMRspectroscopy.

<p>The first part of this thesis describes a synthetic strategythat provides all eight possible isomers of a given vic-aminoalcohol starting from vinylepoxides. The value of a generalroute is evident, as several isomers are needed ininvestigations of structure-activity relationships forpharmacologically active derivatives, and for optimizing theperformance of chiral ligands containing the amino alcoholmoiety.</p><p>Vinylepoxides, obtained in high enantiomeric excess, werering-opened both with inversion and retention ofstereochemistry, delivering two diastereomeric amino alcoholswith high regio- and stereoselectivity. Via ring-closure toaziridines and subsequent regioselective ring-opening withsuitable oxygen nucleophiles, the two remaining amino alcoholswere selectively achieved.</p><p>Within this study, two efficient protocols for theregioselective and stereospecific aminolysis of vinylepoxideshave been presented. Comparedto previous methods, theseprocedures use milder reaction conditions, shorter reactiontimes, generally give higher yields and are applicable to alarger set of substrates. Furthermore, the ring-closure ofvic-amino alcohols to the corresponding N-H vinylaziridines hasbeen investigated. Three routes have been found useful, whichone is preferred depends on substrate and scale.</p><p>In the second part of the thesis, the synthetic strategy isapplied on the synthesis of Sphingosine and its regio- andstereoisomers. Moreover, a rapid way of determining relativeconfiguration of vic-amino alcohols is described, which shouldbe of substantial use when amino alcohols are formed bydiastereoselective reactions.</p><p>amino alcohols, vinylepoxides, vinylaziridines, oxazolines,oxazolidinones, ring-opening, regioselective,diastereoselective, sphingosine, configuration, NMRspectroscopy.</p>

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Une réaction simple de condensation de l'acide thiocyanique avec un cétohexose peut conduire à la formation d'une dizaine de 10 oxazolidinethiones (OZTs) ou oxazolinethiones (OXTs) distinctes. La question que nous nous sommes posée a été "comment gérer une chimie aussi complexe?" Un contrôle attentif des conditions de réaction, associé à des séquences de purification comportant des protections sélectives et diverses fonctionnalisations, peuvent certainement être utiles. Un jeu chimique subtil et stimulant a été développé entre des pré- et post-protections sélectives et des réactions originales de fonctionnalisation. Dans ce travail de thèse, nous avons mis à l'étude de nouvelles tactiques de synthèse et de purification pour accéder à des OZTs et des oxazolidinones (OZOs) ancrées sur des charpentes des cétohexoses. Ces travaux ont été mis en application notamment en série D-fructo et dans les séries épimères D-psico et D-tagato dont la chimie ont été peu explorée en comparaison d'autres séries monosaccharidiques. Nous avons ainsi mieux maîtrisé les approches chimiques permettant d'accéder à ces thionocarbamates saccharidiques et ainsi de valoriser ces molécules dont l'intérêt d'un point de vue biologique et chimique est important. Dans ces études, nous avons élaboré une bibliothèque de formes tautomères fixes de composés hybrides qui ont été soumis à des essais biologiques. Ainsi, ce groupe de composés a fait l'objet de tests antimicrobiens, livrant des résultats très intéressants. Par ailleurs, les meilleurs inhibiteurs de GLUT5 seront utilisés dans le développement de nouveaux outils biochimiques pour une meilleure compréhension des rôles joués par ce transporteur du D-fructose en relation au le diabète de type 2 et de l'obésité.

Made available in DSpace on 2014-06-11T19:30:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-09Bitstream added on 2014-06-13T19:46:55Z : No. of bitstreams: 1 oliveira_clcg_dr_arafcf.pdf: 1338386 bytes, checksum: 1cecdf656a075fad289768bc6e0d0ceb (MD5) / Universidade Estadual Paulista (UNESP) / A linezolida é o primeiro antimicrobiano da classe das oxazolidinonas comercializado mundialmente. O espectro de ação desta molécula envolve a ação contra bactérias gram-positivas, anaeróbias, bem como, Mycobacterium turbeculosis. Este trabalho teve como objetivo desenvolver métodos analíticos para linezolida, incluindo métodos físico-químicos e microbiológicos, realizar estudos de dissolução e de estabilidade, bem como dispor de técnicas de identificação para linezolida na forma farmacêutica comprimido e matéria-prima. A análise qualitativa foi realizada por cromatografia em camada delgada, espectrofotometria no ultravioleta (UV), espectrofotometria no Infravermelho (IV), cromatografia líquida de alta eficiência (CLAE) e análise térmica, possibilitando a identificação das amostras. Os métodos de análise quantitativos empregados e validados foram: (i) espectrofotometria no UV a 251 nm, na faixa de concentração de 6,0 -16,0μg/mL no qual foram avaliados os parâmetros de linearidade, precisão, exatidão e seletividade, com teor médio nos comprimidos de 98,7 %; (ii) CLAE, coluna de C18 e fase móvel composta por, ácido acético 1%: metanol: acetonitrila (50:25:25, V/V/V), apresentando ampla linearidade, precisão, exatidão e especificidade, com um teor médio obtido nos comprimidos de 101,36 %; (iii) determinação da potência microbiológica, pelo método de difusão em ágar cilindros em placa, utilizando cepas de Bacillus subtilis ATCC 9372, em que o teor médio nos comprimidos foi 101,96%. Os métodos desenvolvidos não apresentaram diferença estatística para um nível de significância de 1 %. O teste de dissolução foi desenvolvido e validado utilizando água como meio de dissolução e pás a 50 rpm. O perfil de dissolução obtido foi satisfatório, e a cinética de dissolução calculada. Estudo preliminar de estabilidade de linezolida frente... / The antimicrobial agent linezolid is the first class of oxazolidinonas marketed worldwide. The spectrum of action of this molecule involves action against grampositive bacteria, anaerobic, and Mycobacterium turbeculosis. This work aims to develop analytical methodos to quantify linezolid, including physical, chemical and microbiological tests, studies of dissolution and stability, as well as providing technical quality of identification for tablet and raw material. Qualitative analysis performed by thin layer chromatography, UV-spectrophotometry, IV-spectrophotometry, high performance liquid chromatography (HPLC) and thermal analysis, enabling the identification of samples. The methods of quantitative analysis employed and validated were: (i) UV spectrophotometry at 251 nm, in the range of concentration of 6.0-16.0 μg/mL which presented linearity, precision, accuracy and selectivityy, with the average content in tablets of 98.7%, (ii) HPLC, using as stationary phase column of C18 reversed-phase and mobile phase with the following composition, 1% acetic acid: methanol: acetonitrile (50:25:25, V/V/V), a wide linearity, precision, accuracy and specificity, with an average content obtained in tablets of 101.36%. (iii) Agar diffusion bioassay, using strains of Bacillus subtilis ATCC 9372, with the average content in tablets of 101,96 %. The results of assays were treated statistical by analysis of variance (ANOVA) and were found to be linear (r2 = 0.9998) in the selected range of 20-80 μg/mL. The proposed methods showed no statistical difference for a significance level of 1%. The dissolution test was developed and validated using water as a means of dissolution and blades to 50 rpm. The dissolution profile obtained was satisfactory. Preliminary study of stability of linezolid in acidic, alkaline, oxidative, thermal, photolytic and climatic chamber (40°C/75%) conditions... (Complete abstract click electronic access below)

Orientador: Fernando Antonio Santos Coelho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T02:31:10Z (GMT). No. of bitstreams: 1 Rezende_Patricia_D.pdf: 4429618 bytes, checksum: 8b5bb87a85f841dc4aeabf56b44376ea (MD5) Previous issue date: 2007 / Resumo: Este trabalho teve como objetivo sintetizar e avaliar a atividade biológica de algumas 2-oxazolidinonas. As oxazolidinonas são compostos versáteis utilizados na preparação de uma série de outras classes de compostos e são largamente utilizados como auxiliares quirais em sínteses orgânicas assimétricas. Biologicamente são de grande importância por apresentarem efeitos neurolépticos, efeitos psicotrópicos, antialérgicos e antibacterianos. No que se refere a atividade antibacteriana, as oxazolidinonas, apresentam atividade notável contra muitas cepas resistentes de bactérias gram-positivas, através de um novo mecanismo de ação. As oxazolidinonas 4- e 4,5-substituídas oriundas de aldeídos alifáticos e aromáticos foram sintetizadas a partir de adutos de Morita-Baylis-Hillman (MBH), através de duas principais rotas: via rearranjo de Curtius e via reação de ozonólise do aduto de MBH, sendo esta última, resultado de estudos prévios realizados em nosso laboratório. A reprodutibilidade desta rota sintética nos possibilitou a preparação de um intermediário avançado da substância isocitoxazona, um isômero estrutural da citoxazona, uma oxazolidinona que apresenta atividade citocina moduladora sobre células Th2. A partir da rota via Rearranjo de Curtius e através de uma adaptação da mesma, sintetizamos cetonas a, b-saturadas, a partir de adutos de MBH. E finalmente, iniciamos um estudo para a síntese assimétrica de 2- oxazolidinonas, utilizando a base quiral b-isocupreidina. A mesma foi sintetizada e utilizada na reação de MBH na preparação de um aduto de MBH quiral. As oxazolidinonas sintetizadas estão sendo submetidas a ensaios para a determinação da atividade biológica frente a uma série de microorganismos / Abstract: This work has been as main purpose the synthesis and the biological evaluation of some 2-oxazolidinones. These compounds have been used as substrates for the preparation of different compounds and used as chiral auxiliary in asymmetric organic synthesis. Besides the synthetic relevance of this class of compounds, they also exhibit important biological effects, as neuroleptic, psychotropic, anti-allergenic and antibacterial. In the last years, an special attention has been paid to these compounds due to their antibacterial activity, since they show a remarkable activity against Gram-positive drugs multi-resistant strains, through a new action mechanism. In this work several 4- and 4,5-substituted oxazolidinones were synthesized from Morita-Baylis-Hillman prepared from aliphatic and aromatic commercial aldehydes, using two synthetic approaches. The first approach was based on employing a Curtius rearrangement, and the second was based on the utilization of an ozonolysis reaction of the MBH adducts. Both synthetic approaches have permitted preparing several oxazolidinones. An advanced intermediate for the total synthesis of isocytoxazone, a structural isomer of cytoxazone, was also prepared. Cytoxazone, a natural oxazolidinone, exhibits cytocine modulator activity for Th2 cells. Through an adaptation of the strategy based on Curtius rearrangement, we have also synthesized a, b-unsaturated ketones from MBH adducts. Finally, a study was started aiming at synthesizing chiral oxazolidinones, using chiral base b-isocupreidine prepared by us. Synthetic oxazolidinones prepared in this work are under biological screening for evaluating theirs antibacterial profiles / Doutorado / Quimica Organica / Doutor em Ciências

Small chiral molecules are very important building blocks in the synthesis of biologically active compounds. These building blocks include nitrogen and oxygen-containing heterocycles such as 2-oxazolidinones, 1,3-oxazinan-2-ones, 2-oxazolines, oxazines, morpholine and morpholinones. Because of their interesting properties, chiral heterocycles have stirred great interest in the synthetic chemist community to develop useful and efficient strategies to these molecules. In this dissertation, the design and syntheses of various heterocyclic building blocks are presented, as well as the testing of their biological activities as antibacterial. Another very interesting family of heterocycle-containing molecules are the Aeruginosins. They are a family of marine natural products isolated from a blue-green algae, which display inhibitory activity against serine proteases such as thrombin, trypsin, and factor VIIa. Most aeruginosins contain an heterocyclic moiety called the 2-carboxy-6-hydroxyoctahydroindole (Choi) ring; this Choi moiety is a rigid bicyclic unnatural amino acid and is the core structure in the aeruginosins, indispensable to their biological activity. A synthesis of a ring-oxygenated variant of the Choi from D-mannose is reported in this dissertation. The ring-oxygenated variant of 2-carboxy-6-hydroxyoctahydroindole can potentially be used as a surrogate of Choi in the design and synthesis of aeruginosin-based thrombin inhibitors.

Orientador: Hérida Regina Nunes Salgado / Banca: Maria Ines Rocha Miritello Santoro / Banca: Gerson Antônio Pianetti / Banca: Magali Conceição Monteiro da Silva / Banca: Magali Benjamin de Araújo / Resumo: A linezolida é o primeiro antimicrobiano da classe das oxazolidinonas comercializado mundialmente. O espectro de ação desta molécula envolve a ação contra bactérias gram-positivas, anaeróbias, bem como, Mycobacterium turbeculosis. Este trabalho teve como objetivo desenvolver métodos analíticos para linezolida, incluindo métodos físico-químicos e microbiológicos, realizar estudos de dissolução e de estabilidade, bem como dispor de técnicas de identificação para linezolida na forma farmacêutica comprimido e matéria-prima. A análise qualitativa foi realizada por cromatografia em camada delgada, espectrofotometria no ultravioleta (UV), espectrofotometria no Infravermelho (IV), cromatografia líquida de alta eficiência (CLAE) e análise térmica, possibilitando a identificação das amostras. Os métodos de análise quantitativos empregados e validados foram: (i) espectrofotometria no UV a 251 nm, na faixa de concentração de 6,0 -16,0μg/mL no qual foram avaliados os parâmetros de linearidade, precisão, exatidão e seletividade, com teor médio nos comprimidos de 98,7 %; (ii) CLAE, coluna de C18 e fase móvel composta por, ácido acético 1%: metanol: acetonitrila (50:25:25, V/V/V), apresentando ampla linearidade, precisão, exatidão e especificidade, com um teor médio obtido nos comprimidos de 101,36 %; (iii) determinação da potência microbiológica, pelo método de difusão em ágar cilindros em placa, utilizando cepas de Bacillus subtilis ATCC 9372, em que o teor médio nos comprimidos foi 101,96%. Os métodos desenvolvidos não apresentaram diferença estatística para um nível de significância de 1 %. O teste de dissolução foi desenvolvido e validado utilizando água como meio de dissolução e pás a 50 rpm. O perfil de dissolução obtido foi satisfatório, e a cinética de dissolução calculada. Estudo preliminar de estabilidade de linezolida frente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The antimicrobial agent linezolid is the first class of oxazolidinonas marketed worldwide. The spectrum of action of this molecule involves action against grampositive bacteria, anaerobic, and Mycobacterium turbeculosis. This work aims to develop analytical methodos to quantify linezolid, including physical, chemical and microbiological tests, studies of dissolution and stability, as well as providing technical quality of identification for tablet and raw material. Qualitative analysis performed by thin layer chromatography, UV-spectrophotometry, IV-spectrophotometry, high performance liquid chromatography (HPLC) and thermal analysis, enabling the identification of samples. The methods of quantitative analysis employed and validated were: (i) UV spectrophotometry at 251 nm, in the range of concentration of 6.0-16.0 μg/mL which presented linearity, precision, accuracy and selectivityy, with the average content in tablets of 98.7%, (ii) HPLC, using as stationary phase column of C18 reversed-phase and mobile phase with the following composition, 1% acetic acid: methanol: acetonitrile (50:25:25, V/V/V), a wide linearity, precision, accuracy and specificity, with an average content obtained in tablets of 101.36%. (iii) Agar diffusion bioassay, using strains of Bacillus subtilis ATCC 9372, with the average content in tablets of 101,96 %. The results of assays were treated statistical by analysis of variance (ANOVA) and were found to be linear (r2 = 0.9998) in the selected range of 20-80 μg/mL. The proposed methods showed no statistical difference for a significance level of 1%. The dissolution test was developed and validated using water as a means of dissolution and blades to 50 rpm. The dissolution profile obtained was satisfactory. Preliminary study of stability of linezolid in acidic, alkaline, oxidative, thermal, photolytic and climatic chamber (40°C/75%) conditions... (Complete abstract click electronic access below) / Doutor

La réaction d’amination de liens C-H, impliquant la transformation directe d’un lien C-H en lien C-N constitue une approche synthétique d’avenir pour la préparation de composés azotés. L’application de cette stratégie de manière intramoléculaire apparaît comme une approche puissante pour la synthèse de composés hétérocycliques. En particulier, les oxazolidinones, carbamates cycliques à cinq chaînons, constituant une nouvelle classe d’antibiotiques très prometteuse, pourraient être synthétisées par cette méthode. Il y a moins d’une dizaine d’années, notre groupe de recherche a travaillé sur le développement de méthodologies utilisant des espèces nitrènes métalliques pour l’amination intra et intermoléculaire. Les N-tosyloxycarbamates, en présence d’une base et d’un catalyseur dimère de rhodium (II) tétracarboxylate sont les précurseurs de ces espèces nitrènes métalliques, capables de faire l’insertion de liens C(sp3)-H. Dans ces travaux de thèse, nous avons travaillé sur le développement d’une méthode plus « verte » d’amination intramoléculaire. Les N-mésyloxycarbamates, plus légers que leurs homologues N-tosyloxycarbamates, ont été identifiés comme d’excellents précurseurs de nitrènes. La méthodologie développée ne nécessite que 3 mol % de dimère de rhodium Rh2(tpa)4 et de 1,5 équivalents de solution aqueuse saturée de K2CO3, le tout dans l’acétate d’éthyle et donne de bons rendements de cyclisation. Une étude de l’étendue réactionnelle a été effectuée, montrant la tolérance et les limitations de notre système catalytique : les hétéroatomes ne posent pas de problèmes hormis l’atome d’azote, qui doit être protégé afin de garantir la transformation. En outre, nous avons constaté que les liens C-H aliphatiques secondaires sont moins réactifs que les liens tertiaires. Après avoir tenté de développer des conditions réactionnelles spécifiques aux liens C-H non activés, nous avons montré la possibilité d’aminer des liens C-H propargyliques de manière chimiosélective ; la triple liaison C-C peut ensuite être dérivatisée efficacement, donnant accès à la formule saturée correspondante ainsi qu’à d’autres motifs. Dans un désir de substituer les complexes de rhodium par d’autres complexes de métaux plus abondants et moins dispendieux, nous nous sommes tournés, dans un premier temps, vers les complexes de fer et par la suite, vers les pinceurs de nickel. Les phtalocyanines de fer ont été identifiées comme étant de bons catalyseurs de l’amination intramoléculaire de N-mésyloxycarbamates. Le chlorure de phtalocyanine de fer (III), en présence d’un sel de AgBF4 et de K2CO3, dans le 1,1,2,2-tétrachloroéthane anhydre, permet l’obtention de la 4-phenyloxazolidin-2-one avec 63% de rendement. En outre, il est possible d’atteindre un rendement de 49% à partir du même substrat N-mésyloxycarbamate, par catalyse avec un pinceur de nickel de type POCN, en présence d’un sel de mésylate. Des indices sur le mécanisme des ces deux transformations ont pu être recueillis lors de la courte étude de ces systèmes. / C-H amination reactions, i.e. the direct transformation of a C-H bond into a C-N bond, represents a very promising synthetic approach to prepare nitrogen-containing compounds. The strategy, when applied to intramolecular transformations, represents a powerful method for the preparation of heterocycles. In particular, oxazolidinones (5-membered carbamate heterocycles), which are a novel class of promising antimicrobials, could be easily accessed using C-H amination. Nearly a decade ago, our research group developed methods for metal nitrene-mediated C-H aminations, for both intra- and intermolecular transformations. N-Tosyloxycarbamates, in the presence of a tetracarboxylate rhodium (II) dimer catalyst and a base, were found to be good precursors to metal nitrenes; the latter being able to perform C(sp3)-H insertions. In the present thesis, we have worked on developing a “greener” method for C-H amination reactions. N-Mesyloxycarbamates, lighter than their N-tosyloxycarbamate homologues, were identified as nitrene precursors. The methodology requires only 3 mol % of rhodium dimer Rh2(tpa)4 and 1.5 equivalents of an aqueous saturated solution of K2CO3, in AcOEt and provides the cyclized product in good yields. The scope of the reaction was investigated, illustrating the tolerance and limitations of the catalytic system: heteroatoms are not a problem except for nucleophilic nitrogens, which should be protected, in order to allow for efficient transformation. We observed that secondary C-H bonds were less reactive than tertiary ones. After attempting to develop specific conditions for non-activated bonds, we showed that propargylic C-H bonds can be chemoselectively aminated; and the C-C triple bond can easily be further derivatized, allowing for structural diversification. With regards to replacing rhodium complexes by complexes of other metals, which are more abundant and cheaper, we focused first on iron complexes and then on nickel pincer complexes. Iron phthalocyanin complexes are viable catalysts for the intramolecular C-H amination using N-mesyloxycarbamates. Iron (III) phthalocyanin chloride, along with AgBF4 salt and K2CO3, in anhydrous 1,1,2,2-tetrachloroethane, allows the formation of phenyloxazolidin-2-one in 63% yield. Likewise, the same product can be generated in 49% yield, when a POCN nickel pincer is used as a catalyst, along with a sodium mesylate salt and a base, in anhydrous DCM. Some mechanistic clues could be collected while studying the catalytic systems.