A presente tese descreve a síntese e caracterização de 10 novas séries de moléculas na forma de banana contendo os anéis isoxazolina e isoxazol como reais candidatos na preparação de cristais líquidos polares. Foram avaliados parâmetros estruturais tais como o tipo de função conectora do centro curvado com os braços mesogênicos, a natureza do heterociclo e a sua posição relativa ao núcleo. A síntese dos compostos contou com a metodologia de preparação do anel isoxazolina, a cicloadição [3+2] 1,3-dipolar entre alcenos e óxidos de nitrila, os quais foram gerados pelas oximas preparadas a partir de aldeídos alifáticos e aromáticos. Todas as isoxazolinas foram oxidadas aos seus respectivos isoxazóis utilizando dióxido de manganês. Foram utilizadas ainda reações de alquilação, redução, desproteção, hidrogenólise, olefinação, adição de aminas à aldeídos e esterificação. Todas as moléculas sintetizadas foram caracterizadas por RMN de 1H e 13C, além de serem observadas por MOLP para determinação dos seus pontos de fusão. As moléculas que apresentaram comportamento mesomórfico foram ainda caracterizadas por DSC, XRD e voltagem triangular. No capítulo 3 é descrita a síntese dos isoftalatos 19a-b, 20a-b, 26a-b e 27a-b. No subgrupo dos Isoftalatos derivados de isoxazóis e isoxazolinas 3,5-diarilsubstituídos foi possível a síntese apenas do composto 11d que não apresentou comportamento líquido cristalino No subgrupo dos isoftalatos derivados de isoxazóis e isoxazolinas 3-alquil-5-arilsubstituídos as isoxazolinas 19a-b não apresentaram comportamento líquido-cristalino. Foram encontradas mesofases para os compostos 20a-b que ainda não foram determinadas com as técnicas disponíveis. Os isoxazóis 20a-b apresentaram uma provável Blue Phase logo após o resfriamento do isotrópico, que rapidamente se converte em uma provável mesofase monotrópica ferroelétrica com texturas e padrão de XRD peculiares até então não observada na literatura. No subgrupo dos isoftalatos derivados de isoxazóis e isoxazolinas 3-aril-5-alquilsubstituídos 26a-b e 27a-b não foi observado comportamento líquido-cristalino. O capítulo 4 descreve a síntese das isoftaliminas 35, 36, 44, 45, 50a-b, 51a-b, 56a-d, 57a-d, 63a-b e 64a-b. No subgrupo dos isoxazóis e isoxazolinas 3,5-diarilsubstituídos 35, 36, 44 e 45 foram observadas as mesofases B7 e B1 apenas com a inversão da orientação do anel isoxazol como braçomesogênicos dos compostos finais, enquanto que as isoxazolinas não apresentaram mesofases. A mesofase B7 do composto 36 apresentou comportamento antiferroelétrico enquanto que a mesofase B1 do composto 45 não mostrou resposta frente ao campo elétrico aplicado, além disso, o XRD mostrou que tal mesofase colunar B1 pode ser uma fase 3D modulada. No subgrupo das isoxazolinas e isoxazóis 3-alquil-5-arilsubstituídos 50a-b e 51a-b foram observadas fases do tipo DC para as isoxazolinas 50a-b, a qual deve ser confirmada por FFTEM. No subgrupo dos materiais 3-aril-5-alquilsubstituídos 56a-d, 57a-d, 63a-b e 64a-b foram observadas mesofases SmXPF para os compostos 56b-d. Os isoxazóis 57a-d apresentaram texturas similares, porém não apresentaram mesofase, mas os mesmos seguem o mesmo padrão de difração das isoxazolinas do capítulo 3. Apenas a isoxazolina 63b dos compostos perfluorados apresentou mesofase No capítulo 5 é descrita a síntese de ésteres não-simétricos contendo os heterociclos isoxazol e isoxazolinas como núcleo central 71a-f, 82, 83, 84 e 85. No primeiro subgrupo todos os ésteres cinâmicos 71a-f apresentaram comportamento mesomórfico com grandes faixas de temperaturas nas mesofases. No segundo subgrupo as isoxazolinas 82 e 83 apresentaram comportamento completamente distinto, onde só foi observada a formação de uma mesofase SmB para o composto que tem a posição éster localizada na direção do nitrogênio do heterociclo. Já os isoxazóis 84 e 85 deste subgrupo apresentaram as mesofases N e SmC em temperaturas bastante similares, porém, a observação desses materiais em uma cela alinhada revelou o crescimento de filamentos na transição N-SmC apenas para o composto 85, o qual também possui a porção éster na direção do nitrogênio do anel isoxazol. O capítulo 6 traz a síntese dos ésteres e iminas simétricos 88, 89, 94 e 95 utilizando os heterociclos como núcleo central, os quais apresentaram mesofases SmC e N. Além disso, o diéster 89 derivado de isoxazol apresentou a mesma característica que o composto 85 do capítulo 5, apresentando uma transição N-SmC com crescimento de filamentos perpendiculares à direção de alinhamento da amostra dentro da cela, podendo estar relacionada à uma mesofase NTB. / This thesis describe the synthesis and characterization of 10 new series of banana shaped molecules containing the isoxazoline and isoxazole rings as real players for preparation of polar liquid crystals. It was evaluate structural parameters such as the type of connecting function of the bent core with the mesogenic arms, the heterocycle nature and its position relative to the central core. The synthesis of the compounds included the methodology of preparation of the isoxazoline ring, the [3 + 2] 1,3-dipolar cycloaddition between alkenes and nitrile oxides, which were generated by the oximes prepared from aliphatic and aromatic aldehydes. Furthermore, all isoxazolines were oxidized to its respective isoxazoles using manganese dioxide. Besides the described methodologies, alkylation, reduction, deprotection, hydrogenolysis, olefination, addition of amines to the aldehydes and esterification reactions were used. All the synthesized molecules were characterized by 1H NMR and 13C NMR, and also observed by POM for determination of its melting points. The molecules previously analyzed by POM that showed mesomorphic behavior were characterized by DSC, XRD and triangular voltage still. Chapter 3 describes the synthesis of isophthalates 19a-b, 20a-b, 26a-b e 27a-b. In the subgroup of isophthalates derived from isoxazoles and isoxazolines 3,5-diarylsubstituted it was possible to synthesize only compound 11d which did not show liquid crystalline behavior In the subgroup of the isophthalates derived from isoxazoles and isoxazolines 3-alkyl-5-arylsubstituted the isoxazolines 19a-b did not show liquid crystalline behavior. It was found mesophases for compounds 20a-b that still could not be determined with the available techniques. The isoxazoles 20a-b presented a probable Blue Phase soon after cooling from the isotropic which quickly converts into a probable ferroelectric monotropic mesophase with peculiar textures and pattern of XRD until then not observed in the literature. In the subgroup of the isophthalates of isoxazoles and isoxazolines 3-aryl-5-alkylsubstituted 26a-b and 27a-b no liquid crystalline behavior was observed. Chapter 4 describes the synthesis of isophthalimines 35, 36, 44, 45, 50a-b, 51a-b, 56a-d, 57a-d, 63a-b and 64a-b. In the subgroup of the isoxazoles 3,5-diarylsubstituted 35, 36, 44 and 45 the B7 and B1 mesophases were observed only with the inversion of the isoxazole ring orientation as mesogenic arm of thefinal compounds whereas the isoxazolines did not present mesophases. The B7 mesophase of the compound 36 showed antiferroelectric switching while the B1 mesophase of the compound 45 showed no response to the applied electric field, in addition, the XRD showed that such B1 columnar mesophase could be a 3D modulated phase one. In the subgroup of 3-alkyl-5-arylsubstituted isoxazolines and isoxazoles 50a-b and 51a-b DC phases were observed for isoxazolines 50a-b which should be confirmed by FFTEM. The SmXPF mesophase were observed for componds 56b-d in the subgroup of 3-aryl-5-alkylsubstituted materials 56a-d, 57a-d, 63a-b e 64a-b. The isoxazoles 57a-d presented similar textures although did not showed mesophase, but they follow the same diffraction pattern of the chapter 3 isoxazolines. Only the isoxazoline 63b of the perfluorinated compounds showed mesophase In chapter 5 is described the synthesis of non-symmetric esters containing isoxazol and isoxazolines heterocycles as central core 71a-f, 82, 83, 84 e 85. In the first subgroup all the cinnamic esters 71a-f showed mesomorphic behavior with large mesophases temperature ranges. In the second subgroup the isoxazolines 82 and 83 showed completely different behavior which only was observed the SmB mesophase formation for compound having the ester position towards the heterocycle nitrogen. Furthermore, the isoxazoles 84 and 85 of this subgroup showed the N and SmC mesophases at very similar temperatures, however, the observation of these materials in an aligned cell revealed the filamentary growth in the N-SmC transition only for compound 85, which also has the ester moiety in the direction of the isoxazole ring nitrogen. Chapter 6 brings forward the synthesis of symmetrical esters and imines 88, 89, 94 and 95 using the heterocycles as the central cores, which showed SmC and N mesophases. Moreover, the isoxazole derived diester 89 showed the same feature as compound 85 of Chapter 5, exhibiting a N-SmC transition with filament growth perpendicular to the rubbing direction of the cell which may be related to a NTB mesophase.

La Ribavirine est un analogue nucléosidique de la guanosine constitué d'un ribose et d'un noyau triazole. Cet antiviral, synthétisé en 1970, possède une activité contre différents virus comme le virus respiratoire syncytial chez les enfants en détresse respiratoire, les virus des hépatites B et E, ainsi que contre certains cancers et leucémies. Elle est surtout connue pour son utilisation dans le traitement de l'hépatite C, en combinaison avec l'Interféron. Cependant, l'efficacité de cette thérapie est limitée à certains génotypes du virus et les effets secondaires résultants sont nombreux. C'est pourquoi il est nécessaire de trouver d'autres analogues actifs contre l'hépatite C et moins toxiques afin d'offrir un traitement aux 170 millions d'individus atteints de cette maladie chronique et pouvant évoluer vers des cirrhoses et des cancers du foie. Par une méthodologie d'alcynylglycosylation médiée à l'indium suivie d'une cycloaddition 1,3 dipolaire, des C-nucléosides analogues de la Ribavirine ont été synthétisés. L'un deux, SRO-91, a montré une activité antivirale comparable à celle de la Ribavirine vis-à-vis de l'ARN polymérase du virus de l'hépatite C. L'objectif de cette thèse est donc de synthétiser d'autres C-nucléosides analogues sur le modèle de SRO-91. Des modifications ont été effectuées autant sur le ribose que sur le noyau triazole. Concernant les transformations du ribose, nous nous sommes intéressés à la position C2', notamment en introduisant une quaternisation avec différents groupements (CH3, CF3, F …) ou bien en désoxygénant cette position. Cette thèse décrit les différentes stratégies explorées pour la synthèse de plusieurs de ces C-nucléosides dont les activités antivirales seront étudiées ultérieurement. / Ribavirin is a nucleosidic analogue of guanosine composed of a ribose and a triazole ring. This antiviral compound, synthesized in 1970, exhibits an activity against a broad-range of viruses such as respiratory syncytial virus in respiratory distress children, hepatitis B and E viruses as well as some cancers and leukemia. It is especially known for its use in hepatitis C treatment in combination with Interferon. However, the efficiency of this therapy is limited to a few genotypes of the virus and leads to numerous side effects. Therefore, finding new efficient and less toxic analogs is necessary to treat the 170 million individuals that are chronically infected and at risk of developing cirrhosis and liver cancer. Thanks to a methodology of indium mediated alcynylglycosylation followed by a 1,3-dipolar cycloaddition, C-nucleosides analogs of Ribavirin have been synthesized. Among them, SRO-91, showed a comparable activity to Ribavirin towards hepatitis C virus ARN polymerase. This thesis' objective is to synthesize other C-nucleosides analogs based on SRO-91 model. Modifications have been made on the triazole ring as well as on the ribose. In regards to the ribose transformations, we have been interested into the C2' position, in particular by introducing a quaternisation with different moieties (CH3, CF3, F …) or by deoxygenating this position. This thesis describes the different strategies explored for the synthesis of some of these C-nucleosides whose antiviral activities will be studied later.

A presente tese descreve a síntese e caracterização de 10 novas séries de moléculas na forma de banana contendo os anéis isoxazolina e isoxazol como reais candidatos na preparação de cristais líquidos polares. Foram avaliados parâmetros estruturais tais como o tipo de função conectora do centro curvado com os braços mesogênicos, a natureza do heterociclo e a sua posição relativa ao núcleo. A síntese dos compostos contou com a metodologia de preparação do anel isoxazolina, a cicloadição [3+2] 1,3-dipolar entre alcenos e óxidos de nitrila, os quais foram gerados pelas oximas preparadas a partir de aldeídos alifáticos e aromáticos. Todas as isoxazolinas foram oxidadas aos seus respectivos isoxazóis utilizando dióxido de manganês. Foram utilizadas ainda reações de alquilação, redução, desproteção, hidrogenólise, olefinação, adição de aminas à aldeídos e esterificação. Todas as moléculas sintetizadas foram caracterizadas por RMN de 1H e 13C, além de serem observadas por MOLP para determinação dos seus pontos de fusão. As moléculas que apresentaram comportamento mesomórfico foram ainda caracterizadas por DSC, XRD e voltagem triangular. No capítulo 3 é descrita a síntese dos isoftalatos 19a-b, 20a-b, 26a-b e 27a-b. No subgrupo dos Isoftalatos derivados de isoxazóis e isoxazolinas 3,5-diarilsubstituídos foi possível a síntese apenas do composto 11d que não apresentou comportamento líquido cristalino No subgrupo dos isoftalatos derivados de isoxazóis e isoxazolinas 3-alquil-5-arilsubstituídos as isoxazolinas 19a-b não apresentaram comportamento líquido-cristalino. Foram encontradas mesofases para os compostos 20a-b que ainda não foram determinadas com as técnicas disponíveis. Os isoxazóis 20a-b apresentaram uma provável Blue Phase logo após o resfriamento do isotrópico, que rapidamente se converte em uma provável mesofase monotrópica ferroelétrica com texturas e padrão de XRD peculiares até então não observada na literatura. No subgrupo dos isoftalatos derivados de isoxazóis e isoxazolinas 3-aril-5-alquilsubstituídos 26a-b e 27a-b não foi observado comportamento líquido-cristalino. O capítulo 4 descreve a síntese das isoftaliminas 35, 36, 44, 45, 50a-b, 51a-b, 56a-d, 57a-d, 63a-b e 64a-b. No subgrupo dos isoxazóis e isoxazolinas 3,5-diarilsubstituídos 35, 36, 44 e 45 foram observadas as mesofases B7 e B1 apenas com a inversão da orientação do anel isoxazol como braçomesogênicos dos compostos finais, enquanto que as isoxazolinas não apresentaram mesofases. A mesofase B7 do composto 36 apresentou comportamento antiferroelétrico enquanto que a mesofase B1 do composto 45 não mostrou resposta frente ao campo elétrico aplicado, além disso, o XRD mostrou que tal mesofase colunar B1 pode ser uma fase 3D modulada. No subgrupo das isoxazolinas e isoxazóis 3-alquil-5-arilsubstituídos 50a-b e 51a-b foram observadas fases do tipo DC para as isoxazolinas 50a-b, a qual deve ser confirmada por FFTEM. No subgrupo dos materiais 3-aril-5-alquilsubstituídos 56a-d, 57a-d, 63a-b e 64a-b foram observadas mesofases SmXPF para os compostos 56b-d. Os isoxazóis 57a-d apresentaram texturas similares, porém não apresentaram mesofase, mas os mesmos seguem o mesmo padrão de difração das isoxazolinas do capítulo 3. Apenas a isoxazolina 63b dos compostos perfluorados apresentou mesofase No capítulo 5 é descrita a síntese de ésteres não-simétricos contendo os heterociclos isoxazol e isoxazolinas como núcleo central 71a-f, 82, 83, 84 e 85. No primeiro subgrupo todos os ésteres cinâmicos 71a-f apresentaram comportamento mesomórfico com grandes faixas de temperaturas nas mesofases. No segundo subgrupo as isoxazolinas 82 e 83 apresentaram comportamento completamente distinto, onde só foi observada a formação de uma mesofase SmB para o composto que tem a posição éster localizada na direção do nitrogênio do heterociclo. Já os isoxazóis 84 e 85 deste subgrupo apresentaram as mesofases N e SmC em temperaturas bastante similares, porém, a observação desses materiais em uma cela alinhada revelou o crescimento de filamentos na transição N-SmC apenas para o composto 85, o qual também possui a porção éster na direção do nitrogênio do anel isoxazol. O capítulo 6 traz a síntese dos ésteres e iminas simétricos 88, 89, 94 e 95 utilizando os heterociclos como núcleo central, os quais apresentaram mesofases SmC e N. Além disso, o diéster 89 derivado de isoxazol apresentou a mesma característica que o composto 85 do capítulo 5, apresentando uma transição N-SmC com crescimento de filamentos perpendiculares à direção de alinhamento da amostra dentro da cela, podendo estar relacionada à uma mesofase NTB. / This thesis describe the synthesis and characterization of 10 new series of banana shaped molecules containing the isoxazoline and isoxazole rings as real players for preparation of polar liquid crystals. It was evaluate structural parameters such as the type of connecting function of the bent core with the mesogenic arms, the heterocycle nature and its position relative to the central core. The synthesis of the compounds included the methodology of preparation of the isoxazoline ring, the [3 + 2] 1,3-dipolar cycloaddition between alkenes and nitrile oxides, which were generated by the oximes prepared from aliphatic and aromatic aldehydes. Furthermore, all isoxazolines were oxidized to its respective isoxazoles using manganese dioxide. Besides the described methodologies, alkylation, reduction, deprotection, hydrogenolysis, olefination, addition of amines to the aldehydes and esterification reactions were used. All the synthesized molecules were characterized by 1H NMR and 13C NMR, and also observed by POM for determination of its melting points. The molecules previously analyzed by POM that showed mesomorphic behavior were characterized by DSC, XRD and triangular voltage still. Chapter 3 describes the synthesis of isophthalates 19a-b, 20a-b, 26a-b e 27a-b. In the subgroup of isophthalates derived from isoxazoles and isoxazolines 3,5-diarylsubstituted it was possible to synthesize only compound 11d which did not show liquid crystalline behavior In the subgroup of the isophthalates derived from isoxazoles and isoxazolines 3-alkyl-5-arylsubstituted the isoxazolines 19a-b did not show liquid crystalline behavior. It was found mesophases for compounds 20a-b that still could not be determined with the available techniques. The isoxazoles 20a-b presented a probable Blue Phase soon after cooling from the isotropic which quickly converts into a probable ferroelectric monotropic mesophase with peculiar textures and pattern of XRD until then not observed in the literature. In the subgroup of the isophthalates of isoxazoles and isoxazolines 3-aryl-5-alkylsubstituted 26a-b and 27a-b no liquid crystalline behavior was observed. Chapter 4 describes the synthesis of isophthalimines 35, 36, 44, 45, 50a-b, 51a-b, 56a-d, 57a-d, 63a-b and 64a-b. In the subgroup of the isoxazoles 3,5-diarylsubstituted 35, 36, 44 and 45 the B7 and B1 mesophases were observed only with the inversion of the isoxazole ring orientation as mesogenic arm of thefinal compounds whereas the isoxazolines did not present mesophases. The B7 mesophase of the compound 36 showed antiferroelectric switching while the B1 mesophase of the compound 45 showed no response to the applied electric field, in addition, the XRD showed that such B1 columnar mesophase could be a 3D modulated phase one. In the subgroup of 3-alkyl-5-arylsubstituted isoxazolines and isoxazoles 50a-b and 51a-b DC phases were observed for isoxazolines 50a-b which should be confirmed by FFTEM. The SmXPF mesophase were observed for componds 56b-d in the subgroup of 3-aryl-5-alkylsubstituted materials 56a-d, 57a-d, 63a-b e 64a-b. The isoxazoles 57a-d presented similar textures although did not showed mesophase, but they follow the same diffraction pattern of the chapter 3 isoxazolines. Only the isoxazoline 63b of the perfluorinated compounds showed mesophase In chapter 5 is described the synthesis of non-symmetric esters containing isoxazol and isoxazolines heterocycles as central core 71a-f, 82, 83, 84 e 85. In the first subgroup all the cinnamic esters 71a-f showed mesomorphic behavior with large mesophases temperature ranges. In the second subgroup the isoxazolines 82 and 83 showed completely different behavior which only was observed the SmB mesophase formation for compound having the ester position towards the heterocycle nitrogen. Furthermore, the isoxazoles 84 and 85 of this subgroup showed the N and SmC mesophases at very similar temperatures, however, the observation of these materials in an aligned cell revealed the filamentary growth in the N-SmC transition only for compound 85, which also has the ester moiety in the direction of the isoxazole ring nitrogen. Chapter 6 brings forward the synthesis of symmetrical esters and imines 88, 89, 94 and 95 using the heterocycles as the central cores, which showed SmC and N mesophases. Moreover, the isoxazole derived diester 89 showed the same feature as compound 85 of Chapter 5, exhibiting a N-SmC transition with filament growth perpendicular to the rubbing direction of the cell which may be related to a NTB mesophase.

This thesis is divided into three separate parts with amino alcohols as the common feature. The first part describes the development of a novel three-component approach to the synthesis of α-hydroxy-β-amino esters. Utilizing a highly diastereoselective Rh(II)-catalyzed 1,3-dipolar cycloaddition of carbonyl ylides to various aldimines, syn-α-hydroxy-β-amino esters formed in high yields and excellent diastereoselectivities. This methodology was also applied in a short enantioselective synthesis of the C-13 side-chain of Taxol. The second part of the thesis describes a total synthesis of D-erythro- Sphingosine based on a cross-metathesis approach to assemble the polar head group and the aliphatic chain. The last part deals with the application of amino alcohols as scaffolds in a diversity-oriented protocol for the development of libraries of small polycyclic molecules. The design of the libraries is based on the iterative use of two powerful ring-forming reactions; a ring-closing metathesis and an intramolecular Diels-Alder reaction, to simultaneously introduce structural complexity and diversity. / QC 20101222

Notre équipe a récemment décrit la synthèse de nouveaux iminosucres de type indolizidines et quinolizidines, qui se sont avérés être de puissants inhibiteurs sélectifs d’α-glucosidases (IC50 nanomolaires). Ces molécules, de structure originale, ont la particularité de posséder un centre quaternaire en jonction de cycles et une configuration D-gluco. Dans le but de mieux comprendre le mode d’interaction de ces molécules avec les glycosidases, nous nous sommes intéressés à la synthèse de leurs analogues comportant un motif aziridine, inclus dans un squelette 1 azabicyclo[4.1.0]heptane.L’approche synthétique que nous avons choisie pour accéder aux aziridinyl iminosucres implique une cycloaddition 1,3-dipolaire régio- et stéréoselective de cétonitrones dérivées de sucres avec des alcynes pour former des isoxazolines et un réarrangement de Baldwin stéréosélectif en 2 acylaziridines. Pour les acylaziridines polybenzylées la conversion en aziridinyl iminosucres a été effectuée par réduction diastéréosélective de leur fonction cétone et déprotection dans des conditions réductrices de Birch. Pour les acylaziridines polyacétylées les iminosucres finaux ont été obtenus par réduction en présence d’hydrures métalliques.Grâce à cette stratégie de synthèse originale, efficace, et économique en atomes, nous avons préparés 7 aziridinyl iminosucres, et 5 isoxazolines polyhydroxylées. Tous ces nouveaux iminosucres ont été évalués comme inhibiteurs de glycosidases, et se sont avérées être des inhibiteurs moyens (IC50 micromolaires) mais sélectifs des α-glucosidases. L’obtention de complexes cristallins avec une α-glucosidase bactérienne a permis de montrer par cristallographie leur mode d’interaction avec cette enzyme, à l’échelle moléculaire. / Our team has recently described the synthesis of new indolizidine and quinolizidine iminosugars, which revealed to be potent and selective α-glucosidase inhibitors (nanomolar IC50). These original molecules exhibit a quaternary center at the ring junction and a D-gluco configuration. With the aim to define the mode of interaction of these molecules with glycosidases, we engaged in the synthesis of analogues containing an aziridine moiety included in a 1-azabicyclo[4.1.0]heptane scaffold.Our synthetic approach towards aziridinyl iminosugars involves a stereoselective 1,3-dipolar cycloaddition between carbohydrate-derived cyclic ketonitrones and alkynes, and a stereoselective Baldwin rearrangement into 2-acylaziridines. The latter (if polybenzylated) were converted into aziridinyl iminosugars through diastereoselective reduction of their ketone function and deprotection under Birch conditions. In the case of polyacetylated acylaziridines, the final iminosugars were obtained by reduction with hydrides.Using this strategy, we have prepared 7 aziridinyl iminosugars, and 5 polyhydroxylated isoxazolines. All these new iminosugars were evaluated as glycosidase inhibitors, and they revealed to be modest (micromolar IC50) but selective inhibitors of α-glucosidases. Their complexes with a crystalline bacterial α-glucosidase allowed crystallographic elucidation of their mode of interaction with this enzyme at the molecular level.

[pt] A importância terapêutica dos compostos contendo 1,2,3-triazóis deve-se ao seu espectro de atuação farmacológica, entre as quais podemos destacar a ação anticâncer, antiviral, antibacteriana, antifúngica, anticonvulsivante entre outras. A facilidade sintética de obtenção de 1,2,3- triazóis por meio da reação de cicloadição 1,3 –dipolar catalisada por cobre (CuAAc), também denominada click chemistry, bem como a reação de cicloadição térmica 1,3-dipolar, torna este grupo bastante atraente como um grupo farmacofórico. O presente trabalho tem como objetivo geral o planejamento, síntese e avaliação de fenil(1-fenil-1H-1,2,3-triazóis-4-il)metanol, também denominados hidróxi-1,2,3-triazóis, visando analisar suas ações farmacológicas frente a leishmaniose. Duas estratégias foram desenvolvidas para a obtenção destes compostos: (i) reação de cicloadição 1,3-dipolar catalisada por cobre (CuAAC) entre 1-fenil-3-(trimetilsilil)prop-2-in-1-óis e aril azidas substituídas previamente preparadas levando assim a obtenção dos fenil(1-fenil-1H-1,2,3-triazóis-4-il)metanol com rendimentos entre 20 e 30 por cento. As aril azidas foram preparadas à partir das anilinas em 60 a 85 por cento de rendimentos e os 1-fenil-3-(trimetilsilil)prop-2-in-1-óis foram preparados à partir da adição de etiniltrimetilsilano aos benzaldeídos comerciais (ii) reação de cicloadição térmica entre aril azidas e (E)-3-(dimetilamino)-1-fenilprop-2-en-1-ona - previamente preparadas à partir de 4-bromoacetofenonas, em rendimentos de 40-50 por cento, seguida de redução dos fenil(1-fenil-1H-1,2,3-triazóis-4-il)metanona com rendimentos variando entre 35-50 por cento levando assim a obtenção dos fenil(1-fenil-1H-1,2,3-triazóis-4-il)metanóis com rendimentos entre 20 e 30 por cento. Os compostos sintetizados foram caracterizados por técnicas de espectroscopia de ressonância magnética nuclear (RMN), infravermelho (IV) e espectrometria de massas (CG-MS). / [en] The therapeutic importance of compounds containing 1,2,3-triazoles is due to their spectrum of pharmacological activity, among which we can highlight the anticancer, antiviral, antibacterial, antifungal, anticonvulsant action, among others. The synthetic facility to obtain 1,2,3-triazoles through the 1,3-dipolar copper-catalyzed cycloaddition reaction (CuAAc), also called click chemistry, as well as the 1,3-dipolar thermal cycloaddition reaction, makes this group quite attractive as a pharmacophoric group. The present work has a general objective the planning, synthesis and evaluation of phenyl (1-phenyl-1H-1,2,3-triazoles-4-yl) methanol, also called hydroxy-1,2,3-triazoles, aiming to analyze their pharmacological actions against leishmaniasis. Two strategies were developed to obtain these compounds: (i) 1,3-dipolar copper-catalyzed cycloaddition reaction (CuAAC) between 1-phenyl-3- (trimethylsilyl) prop-2-in-1-ois and aryl azides substituted previously prepared thus leading to obtaining phenyl (1-phenyl-1H-1,2,3-triazoles-4-yl) methanol with yields between 20 and 30 percent. Aryl azides (50a-i) were prepared from anilines in 60 to 85 percent yields and 1-phenyl-3- (trimethylsilyl) prop-2-in-1-ois were prepared from the addition of ethinyltrimethylsilane to commercial benzaldehydes (ii) thermal cycloaddition reaction between aryl azides and (E) -3- (dimethylamino) -1-phenylprop- 2-en-1-one - previously prepared from 4-bromoacetophenones, in yields of 40-50 percent, followed by reduction of phenyl (1-phenyl-1H-1,2,3-triazoles-4- il) methanone with yields varying between 35-50 percent thus leading to the obtaining of phenyl (1-phenyl-1H-1,2,3-triazoles-4-yl) methanols with yields between 20 and 30 percent. The synthesized compounds were characterized by nuclear magnetic resonance (NMR), infrared (IR) and mass spectrometry (CG-MS) techniques.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Les peptides aldéhydes sont connus comme inhibiteurs de protéases et précurseurs de différentes classes de composés biologiquement actifs. Les méthodes pour leur synthèse impliquent classiquement la transformation d'un précurseur (amide de Weinreb, ester, alcool, acétal) en aldéhyde en étape finale pour éviter l'épimérisation du stéréocentre en position α de l'aldéhyde. En revanche, les β-peptides aldéhydes, plus stables à l’épimérisation, ont été relativement peu explorés. Ils sont généralement obtenus par homologation de l'acide aminé correspondant malgré les faibles rendements, les problèmes d’épimérisation et de nombreuses étapes. Par conséquent, un nouvel accès synthétique aux β-peptides aldéhydes reste toujours un challenge difficile. Sur la base des travaux antérieurs dans notre équipe en hétérocycloaddition diastéréosélective [4+2] et [3+2], nous avons développé au cours de ce doctorat de nouvelles stratégies pour l'accès asymétrique à ces dérivés de β-aminoacides par deux voies complémentaires :1) Une voie utilisant les hétérocycles à six chaînons de type 6-ATO (6-alcoxytétrahydrooxazinone) qui ont été préparés par une réaction d’hétérocycloaddition hautement stéréosélective avec de bons rendements et ed. Ces cycloadduits ont été transformés par transacétalisation vers les aminoacétals intermédiaires «mixtes» ou «symétriques». Ces nouveaux acétals sont des intermédiaires parfaits pour la N-élongation par couplage peptidique, conduisant finalement aux aldéhydes peptidiques β3-C-terminaux monosubstitués. 2) Sur une autre approche, les hétérocycles à cinq chaînons 5-AISO (3,3'-disubstitué 5-alcoxy-isoxazolidines) ont été obtenus par cycloaddition dipolaire-1,3 entre des cétonitrones esters et des éthers vinyliques. Ces composés ont été utilisés avec succès en tant que précurseurs d'aminoaldéhydes β3-disubstitués après l’étape de transprotection de l'atome d'azote, suivie par la copure de la liaison N-O. L’extension asymétrique de l'étape de cycloaddition a été étudiée par des voies énantiosélective et diastéréosélective, ouvrant ainsi l'entrée vers les peptides aldéhydiques β3-disubstitués-C-terminaux énantioenrichis. / Peptide aldehydes are known as protease inhibitors and precursors for many biologically active compounds. Methods for their synthesis involve classically the transformation of a precursor (Weinreb amide, ester, alcohol, acetal) into an aldehyde as one of the final steps to prevent epimerization of the carbon α to the aldehyde. By contrast, β-peptide aldehydes, more stable to epimerization, have been relatively unexplored. They are usually obtained by homologation of the corresponding amino acid despite low yielding steps, an epimerization problem and low number of accessible amino acids. Therefore, new synthetic access to β-peptide aldehydes is still a challenging problem. On the basis of previous work in our team concerning [4+2] and [3+2] diastereoselective cycloadditions, we have developed during this PhD thesis new strategies for the asymmetric access of β-amino acid derivatives by two complementary ways :1) Original six-membered heterocycles 6-ATO (6-alkoxy-tetrahydrooxazinone ) were prepared by a highly stereoselective heterocycloaddition reaction with good yields and de. These cycloadducts were transformed via transacetalisation into both «mixed» and «symmetrical» aminoacetals. Moreover, these new acetals are ideal intermediates for further peptide coupling, leading ultimately to monosubstituted β3-C-terminal peptide aldehydes. 2) By another approach five-membered heterocycles 5-AISO (3,3’-disubstituted 5-alkoxy-isoxazolidines) were obtained via 1,3-dipolar cycloaddition between α-keto ester nitrones and vinyl ether. These compounds were successfully used as precursors of disubstituted β-amino aldehydes after transprotection of the nitrogen atom and N-O cleavage of the isoxazolidine ring. Asymmetric extension of the cycloaddition step was studied by enantioselective and diastereoselective pathways, thus opening unprecedented entry to enantioenriched disubstituted β3,β3-C-terminal peptide aldehydes.

A la suite des nombreux travaux sur l’inhibition de la glycogène phosphorylase (GP) menés au laboratoire et au travers de diverses collaborations, cette thèse décrit en cinq chapitres suivis d’une partie expérimentale détaillée, les dernières avancées en termes de synthèse et d’évaluation biologique des inhibiteurs du site catalytique de la GP. La chapitre I de ce manuscrit est consacrée à la présentation des diabètes et plus particulièrement du diabète de type II dont le traitement, motivation première de ce projet, repose sur la connaissance des mécanismes complexes régulant la glycémie. Les différents inhibiteurs synthétisés sont classés par famille selon leur structure qui associe un aglycone hétérocyclique, susceptible d’affinité pour le canal β proche du site actif de l’enzyme, avec un motif glycopyranosidique, ou glycopyranosylidène dans le cas des motifs spiro. Le chapitre II est consacré aux inhibiteurs spiro-bicycliques tels que les glucopyranosylidène-spiro-1,4,2-oxathiazoles et les glucopyranosylidène-spiro-isoxazolines. Le chapitre III décrit la synthèse de C- et N-glycosyles hétérocycles, principalement des glycopyranosyl-1,2,3-triazoles. Enfin le chapitre IV décrit la fonctionnalisation de 5-halogéno-1,2,3-triazoles 4-substitués par couplages pallado-catalysés qui ont constitué un développement imprévu mais original des travaux. Pour terminer, le chapitre V décrit l’évaluation des molécules préparées en tant qu’inhibiteurs de la glycogène phosphorylase. Les expériences et résultats d’enzymologie, de cristallographie ainsi que les tests cellulaires in vitro et in vivo sur le rat sont présentés / Following many studies lead on the inhibition of glycogen phosphorylase (GP) in our laboratory an trough several collaborations, this thesis describes in five chapters and a detailed experimental section, the most recent advances in the areas of synthesis and biological evaluation of GP’s catalytic site inhibitors. Chapter I is dedicated to the description of diabetes and especially type 2 diabetes of which treatment, the main goal of this project, requires knowledge of the complex mechanisms that regulates glycemia. Synthesized inhibitors are broken down into families according to their structure which associates an heterocyclic aglycon, prone to binding in the β pocket lining the active site, with a glycopyranoside or glycopyranosylidene moiety in the case of spiro compounds. Chapter II focuses on spiro-bicyclic inhibitors such as glucopyranosilidene-spiro-1,4,2-oxathiazoles and glucopranosylidene-spiro-isoxazolines. Chapter III describes the synthesis of C- and N-glycosyl-heterocycles, mainly glycopyranosyl-1,2,3-triazoles. Finally, chapter IV studies the palladium-mediated cross coupling fonctionalization of 4-substituted-5-halogenated-1,2,3-triazoles that represents an unexpected but interesting development of the project. To conclude, chapter V gathers the evaluation of synthesized molecules as GP inhibitors. Enzymology and crystallography as well as in vitro and in vivo experiments are presented