O presente trabalho investiga alguns sulfóxidos β-tia-substituidos quanto à sua basicidade relativa e quanto à sua reatividade em relação aos compostos de Grignard aromáticos. O conjunto de compostos investigados foi o seguinte: metil n-propil sulfóxido, metil metiltiometil sulfóxido, etil butil sulfóxido, etil etiltiometil sulfóxido, etil feniltiometil sulfóxido, fenil feniltiometil sulfóxido e 1,3-ditiolano-1-óxido. É apresentada, inicialmente, uma revisão bibliográfica sôbre dois itens: 1. basicidade de sulfóxidos, e 2. reações de sulfóxidos com compostos de Grignard. São apresentados os valores de constantes de associação para dois sulfóxidos β-tia-substituídos e dois não substituídos correspondentes. Estes valores foram calculados a partir de medidas dos deslocamentos químicos dos prótons do fenol em sistemas ternários sulfóxido -fenol-tetracloreto de carbono, pelo dos métodos de Carper e de Mathur. São apresentadas as reações de quatro sulfóxidos com alguns compostos de Grignard aromáticos, tais como os brometos de fenil-, p-anisil-, p-tolilmagnésio, e descritos os métodos de análise dos compostos formados. São descritas as preparações de cincos sulfóxidos e de alguns produtos autênticos. São fornecidos os resultados de algumas experiências de reações de um sulfóxido β-tia-substituído com brometo de fenilmagnésio em presença de base. É apresentada uma discussão na qual se procura interpretar tanto os resultados da literatura como os nossos. Os resultados obtidos demonstram que: a) Há diminuição de basicidade nos sulfóxidos β-tia-substituidos, em comparação com os não substituidos correspondentes. b) A reação dos sulfóxidos β-tia-substituidos com compostos de Grignard aromáticos fornece os mercaptais dos aldeidos aromáticos correspondentes. c) A reação dos sulfóxidos β-tia-substituidos com reagentes de Grignard e impedida por bases fortes. Os rendimentos dos mercaptais são muito mais baixos do que na ausência de base. d) A fixação do organomagnesiano ocorre inicialmente no grupo sulfinila. Um mecanismo envolvendo um estado de transição cíclico é sugerido para explicar a migração preferencial do anel aromático proveniente do composto de Grignard. / This thesis investigates some β-thia-substituted sulphoxides concerning their relative basicity and reactivity toward aromatic Grignard reagents. The following compounds were investigated: methyl n-propyl sulphoxide, methyl methylthiomethyl sulphoxide, ethyl n-butyl sulphoxide, ethyl ethylthiomethyl sulphoxide, ethyl phenylthiomethyl sulphoxide, phenyl phenylthtomethyl sulphoxide and 1,3-dithiolane-l-oxide. A literature review, containing two topics, is presented: 1) basicity of sulphoxides, 2) reactions of sulphoxides with Grignard reagents. The data of the association constants for two β-thiasubstituted and two corresponding unsubstituted sulphoxides are presented. These values were calculated from the chemical shifts of the phenol protons, measured in the ternary systems sulphoxide -phenol-carbon tetrachloride, by methods of Mathur and Carper. The reactivity of four sulphoxides with some Grignard reagents, such as phenyl-, p-anisyl-, and p-tolylmagnesium bromides including the analyses of the resulting products is presented. The preparation of five sulphoxides and of some authentic products are described. Some experiments, in which the Grignard reaction is performed in basic conditions, are reported. The obtained results are discussed in the light of the literature data. It is shown that: a) There is a decrease in basicity going from the unsubstituted sulphoxides to the corresponding β-thia-substituted ones. b) The reaction of β-thia-substituted sulphoxides lead to the corresponding aromatic aldehydes mercaptals. c) The reaction of the β-thia-substituted sulphoxides is inhibited by the presence of a base. The yields of mercaptals are much lower than in the absence of base. d) The attachment of the Grignard reagent occurs, initially, at sulphinyl group. A mechanism, envolving a cyclic transition state, is suggested, in order to explain the preferential migration of the aromatic ring, which belonged originally to the Grignard reagent.

O presente trabalho investiga alguns sulfóxidos β-tia-substituidos quanto à sua basicidade relativa e quanto à sua reatividade em relação aos compostos de Grignard aromáticos. O conjunto de compostos investigados foi o seguinte: metil n-propil sulfóxido, metil metiltiometil sulfóxido, etil butil sulfóxido, etil etiltiometil sulfóxido, etil feniltiometil sulfóxido, fenil feniltiometil sulfóxido e 1,3-ditiolano-1-óxido. É apresentada, inicialmente, uma revisão bibliográfica sôbre dois itens: 1. basicidade de sulfóxidos, e 2. reações de sulfóxidos com compostos de Grignard. São apresentados os valores de constantes de associação para dois sulfóxidos β-tia-substituídos e dois não substituídos correspondentes. Estes valores foram calculados a partir de medidas dos deslocamentos químicos dos prótons do fenol em sistemas ternários sulfóxido -fenol-tetracloreto de carbono, pelo dos métodos de Carper e de Mathur. São apresentadas as reações de quatro sulfóxidos com alguns compostos de Grignard aromáticos, tais como os brometos de fenil-, p-anisil-, p-tolilmagnésio, e descritos os métodos de análise dos compostos formados. São descritas as preparações de cincos sulfóxidos e de alguns produtos autênticos. São fornecidos os resultados de algumas experiências de reações de um sulfóxido β-tia-substituído com brometo de fenilmagnésio em presença de base. É apresentada uma discussão na qual se procura interpretar tanto os resultados da literatura como os nossos. Os resultados obtidos demonstram que: a) Há diminuição de basicidade nos sulfóxidos β-tia-substituidos, em comparação com os não substituidos correspondentes. b) A reação dos sulfóxidos β-tia-substituidos com compostos de Grignard aromáticos fornece os mercaptais dos aldeidos aromáticos correspondentes. c) A reação dos sulfóxidos β-tia-substituidos com reagentes de Grignard e impedida por bases fortes. Os rendimentos dos mercaptais são muito mais baixos do que na ausência de base. d) A fixação do organomagnesiano ocorre inicialmente no grupo sulfinila. Um mecanismo envolvendo um estado de transição cíclico é sugerido para explicar a migração preferencial do anel aromático proveniente do composto de Grignard. / This thesis investigates some β-thia-substituted sulphoxides concerning their relative basicity and reactivity toward aromatic Grignard reagents. The following compounds were investigated: methyl n-propyl sulphoxide, methyl methylthiomethyl sulphoxide, ethyl n-butyl sulphoxide, ethyl ethylthiomethyl sulphoxide, ethyl phenylthiomethyl sulphoxide, phenyl phenylthtomethyl sulphoxide and 1,3-dithiolane-l-oxide. A literature review, containing two topics, is presented: 1) basicity of sulphoxides, 2) reactions of sulphoxides with Grignard reagents. The data of the association constants for two β-thiasubstituted and two corresponding unsubstituted sulphoxides are presented. These values were calculated from the chemical shifts of the phenol protons, measured in the ternary systems sulphoxide -phenol-carbon tetrachloride, by methods of Mathur and Carper. The reactivity of four sulphoxides with some Grignard reagents, such as phenyl-, p-anisyl-, and p-tolylmagnesium bromides including the analyses of the resulting products is presented. The preparation of five sulphoxides and of some authentic products are described. Some experiments, in which the Grignard reaction is performed in basic conditions, are reported. The obtained results are discussed in the light of the literature data. It is shown that: a) There is a decrease in basicity going from the unsubstituted sulphoxides to the corresponding β-thia-substituted ones. b) The reaction of β-thia-substituted sulphoxides lead to the corresponding aromatic aldehydes mercaptals. c) The reaction of the β-thia-substituted sulphoxides is inhibited by the presence of a base. The yields of mercaptals are much lower than in the absence of base. d) The attachment of the Grignard reagent occurs, initially, at sulphinyl group. A mechanism, envolving a cyclic transition state, is suggested, in order to explain the preferential migration of the aromatic ring, which belonged originally to the Grignard reagent.

Les cyclopropanes sont des motifs structuraux importants en chimie médicinale. Parmi les synthèses existantes du fragment aminocyclopropane, les réactions dérivées de la réaction de Kulinkovich, appliquées aux amides et aux nitriles, sont des méthodes simples d'accès. Cependant, il n'existe pas de version asymétrique efficace. Dans une première partie, l'étude de l'utilisation de complexes de titane optiquement actifs pour la préparation de spirolactames chiraux à partir de cyanoesters a été réalisée. Ce travail a permis de mettre au point une méthode d'évaluation rapide de ligands chiraux dont leur criblage a montré que les composés de la famille du Taddol fournissent les meilleurs excès énantiomériques. L'énantiosélectivité demeure cependant actuellement trop faible pour présenter un intérêt en synthèse. Dans une seconde partie, la synthèses de carbinamines tertiaires, un autre motif important, a été étudié à partir d'acylcyanhydrines et d'organométalliques. En particulier, la synthèse d'une bibliothèque d'acides aminés quaternaires a été entreprise à partir d'hydroxyamides. L'incorporation de deux organométalliques différents sur des acylcyanhydrines a été également effectuée conduisant à l'obtention d'hydroxyamides chiraux sous forme racémique. Enfin, l'emploi de réactifs organozinciques allyliques nous a permis d'accéder à de très bons rendements en produits de double addition. Ces hydroxyamides ont été ensuite valorisés comme précurseurs de plateformes multifonctionnelles pour la ligation chimique. / Cyclopropylamines are important scaffolds in medicinal chemistry. Among the syntheses of the aminocyclopropane moiety, the Kulinkovich-related reactions applied to amides and nitriles furnish straightforward access. However, no efficient asymmetric version has been published to date. In a first part, the study of optically active titanium complexes for the preparation of chiral spirolactams from cyanoesters has been undertaken. This work allowed us to setup a quick evaluation method for chiral ligands whose screening revealed that Taddol and its derivatives lead to the best enantiomeric excesses. However, the enantioselectivity remains too low for synthetic purposes. In a second part, the synthesis of tertiary carbinamines, another important scaffold, has been studied from acylcyanohydrins and organometallics. Notably, the synthesis of a quaternary aminoacids library was achieved. The incorporation of two different organometallics on acylcyanohydrins was also undertaken, leading to the preparation of chiral hydroxyamides in a racemic fashion. Lastly, very good yields in double addition products were obtained by using allylic organozinc reagents. The obtained hydroxyamides were used as precursors of polyfunctional linkers for the chemical ligation.

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

Dans ce mémoire, il sera question de la formation de dérivés pipéridines en utilisant la fragmentation de Grob. Tout d’abord, une introduction sur les alcaloïdes ainsi que sur l’expertise du groupe Charette associée à leur formation démontrera l’importance de ces composés dans le domaine de la chimie organique. Cela sera suivi par un résumé de la fragmentation de Grob incluant les conditions de réactions utilisées, l’importance de la structure de la molécule initiale, les prérequis stéréoélectroniques ainsi que les modifications qui y ont été apportées. Le chapitre 2 sera dédié au développement de la méthodologie c’est-à-dire, à l’optimisation de tous les paramètres jouant un rôle dans la fragmentation de Grob. Par la suite, l’étendue de la réaction ainsi que des explications sur la régiosélectivité et la diastéréosélectivité de la réaction seront fournies. La méthodologie peut être exploitée dans un contexte de synthèse qui sera démontré dans le chapitre 3. De plus, elle servira pour une étude mécanistique qui est encore d’actualité à partir du concept d’effet frangomérique. Finalement, quelques projets futurs, notamment des améliorations possibles de la méthodologie, seront présentés dans le dernier chapitre. Le tout sera suivi d’une conclusion résumant l’ensemble des travaux effectués. / This thesis discusses the formation of piperidine derivatives using the Grob fragmentation. Firstly, an introduction of the important alkaloid family as well as previous work completed by the Charette group towards the synthesis of these compounds will be demonstrated. This will be followed by a summary of the Grob fragmentation including a discussion of the reaction conditions, molecular structures, stereoelectronic requirements and modifications of the Grob fragmentation. Chapter 2 will be dedicated to the development of the methodology and more precisely, to the optimization of all parameters necessary to the reaction. Furthermore, the scope of the reaction and some explanation of the regioselectivity and the diastereoselectivity of the reaction will be discussed. The developed methodology can be used in a total synthesis and will be demonstrated in Chapter 3. Moreover, using the frangomeric effect concept, a mechanistic study on the Grob fragmentation will be discussed. Finally, some future projects, especially possible improvement of the methodology, will be presented in the last chapter. This is followed by a conclusion and a summary of the work completed on this project.

Thesis advisor: Amir H. Hoveyda / Chapter One: An overview of Cu-catalyzed enantioselective allylic substitutions with organometallic reagents. Chapter Two: Development of Cu-catalyzed enantioselective allylic alkylations of allylic chlorides with Grignard reagents for the formation of all-carbon quaternary stereogenic centers is disclosed. Chapter Three: Development of Cu-catalyzed enantioselective allylic substitutions of allylic phosphates with alkyl, aryl, and heterocyclic aluminum reagents for the formation of quaternary stereogenic centers is discussed. / Thesis (MS) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Mixed matrix membranes offer an attractive route to the development of high performance and efficiency membranes required for demanding gas separations. Such membranes combine the advantageous processing characteristics of polymers with the excellent separation productivity and efficiency of molecular sieving materials. This research explores the development of mixed matrix membranes, namely in the form of asymmetric hollow fiber membranes using zeolites as the molecular sieving phase and commercially available high performance polymers as the continuous matrix. Lack of adhesion between the typically hydrophobic polymer and the hydrophilic native zeolite surface is a major hurdle impeding the development of mixed matrix membranes. Silane coupling agents have been used successfully to graft polymer chains to the surface of the zeolite to increase compatibility with the bulk polymer in dense films. However, transitioning from a dense film to an asymmetric structure typically involves significant processing changes, the most important among them being the use of phase separation to form the asymmetric porous structure. During the phase separation, it is believed that hydrophilic sieves can act as nucleating agents for the hydrophilic polymer lean phase. Such nucleation tendencies are believed to lead to the formation of gaps between the polymer and sieve resulting in poor mixed matrix performance. This research focuses on defining procedures and parameters to form successful mixed matrix hollow fiber membranes. The first part of this dissertation describes dope mixing procedures and unsuccessful results obtained using a silane coupling agent to enhance polymer-zeolite adhesion. The next section follows the development of a highly successful surface modification technique, discovered by the author, employing the use of a Grignard reagent. As a test case, two zeolites of different silicon-to-aluminum ratios are successfully modified and used to develop mixed matrix membranes with greatly increased gas separation efficiencies. The broad applicability of the surface treatment is also demonstrated by the successful incorporation of the modified zeolites in a second polymer matrix. The final section of the work describes the novel occurrence of large defects (macrovoids) caused by the presence of large zeolite particles proposing a particle size effect in the formation of such defects.

Chapter 1: Reaction of benzoaldehyde with wittig agents or isophone to build up conjugate carbon chain, then combined with electron acceptor to furnished the chromophores. The charge-transfer chromophores, which have the first molecular hyperpolarizability

Dans ce mémoire, il sera question de la formation de dérivés pipéridines en utilisant la fragmentation de Grob. Tout d’abord, une introduction sur les alcaloïdes ainsi que sur l’expertise du groupe Charette associée à leur formation démontrera l’importance de ces composés dans le domaine de la chimie organique. Cela sera suivi par un résumé de la fragmentation de Grob incluant les conditions de réactions utilisées, l’importance de la structure de la molécule initiale, les prérequis stéréoélectroniques ainsi que les modifications qui y ont été apportées. Le chapitre 2 sera dédié au développement de la méthodologie c’est-à-dire, à l’optimisation de tous les paramètres jouant un rôle dans la fragmentation de Grob. Par la suite, l’étendue de la réaction ainsi que des explications sur la régiosélectivité et la diastéréosélectivité de la réaction seront fournies. La méthodologie peut être exploitée dans un contexte de synthèse qui sera démontré dans le chapitre 3. De plus, elle servira pour une étude mécanistique qui est encore d’actualité à partir du concept d’effet frangomérique. Finalement, quelques projets futurs, notamment des améliorations possibles de la méthodologie, seront présentés dans le dernier chapitre. Le tout sera suivi d’une conclusion résumant l’ensemble des travaux effectués. / This thesis discusses the formation of piperidine derivatives using the Grob fragmentation. Firstly, an introduction of the important alkaloid family as well as previous work completed by the Charette group towards the synthesis of these compounds will be demonstrated. This will be followed by a summary of the Grob fragmentation including a discussion of the reaction conditions, molecular structures, stereoelectronic requirements and modifications of the Grob fragmentation. Chapter 2 will be dedicated to the development of the methodology and more precisely, to the optimization of all parameters necessary to the reaction. Furthermore, the scope of the reaction and some explanation of the regioselectivity and the diastereoselectivity of the reaction will be discussed. The developed methodology can be used in a total synthesis and will be demonstrated in Chapter 3. Moreover, using the frangomeric effect concept, a mechanistic study on the Grob fragmentation will be discussed. Finally, some future projects, especially possible improvement of the methodology, will be presented in the last chapter. This is followed by a conclusion and a summary of the work completed on this project.

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