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Ce travail est une contribution à la synthèse de nouvelles plates-formes bishétérocycliques à base de glucide et d’hétérocycles azotés et à l’étude de leur fonctionnalisation en vue d’accéder à des peptidomimétiques. En partant d’un céto-sucre a,ß-insaturé, il est possible d’accéder rapidement à des plates-formes présentant des hétérocycles de type pyrazole et pyrimidine fusionnés à un pyranose. Dans un premier temps, nous avons présenté l’étude de la réactivité de la plate-forme pyrazolopyranoside qui nous a amené à proposer une nouvelle voie d’accès à une série de pyrazoles chiraux hautement fonctionnalisés. Une seconde partie de notre travail consiste en la fonctionnalisation de la plate-forme SMe-pyrimidino-pyranoside par réactions de couplages pallado-catalysées de type Suzuki et Stille sur la partie hétérocycle pyrimidine. La fonctionnalisation de la partie pyranose a été étudiée par coupure du benzylidène suivie de l’alkylation régiosélective de l’alcool en position 4 ou 6. Enfin, cette plate-forme SMepyrimidino-pyranoside présente trois points d’introduction de diversité moléculaire et apparaît comme un outil intéressant pour la construction de peptidomimétiques. Un exemple de son utilisation pour la synthèse de mimes moléculaires du tripeptide RGD a été developpé. / The objective of this work consists in constructing new bicyclic carbohydrate based scaffolds and studying their potential functionalization for peptidomimetic design. Starting from a a,ß-unsaturated sugar-ketone, we describe a rapid access to pyrazolo-pyranoside and pyrimidino-pyranoside compounds. Firstly, we present the functionalization of the pyrazolo-pyranoside platform which under acidic condition, undergo pyranoside ring-opening generating highly functionalized optically pure pyrazoles. Secondly part, the platform SMe-pyrimidino-pyranoside was functionalized by pallado-catalyzed cross-coupling reactions (Suzuki and Stille) on the pyrimidine ring. The functionalization of the pyranose system was carried out by regioselective alkylation. Finally, we use the SMe-pyrimidino-pyranoside platform for the construction of peptidomimetics of the RGD tripeptide.

Thesis advisor: James P. Morken / 1,1-Bis(boronic) esters have attracted significant attention these days due to their unique reactivity. In this thesis, I will show that readily available reagents can undergo deborylative alkylation to deliver synthetically useful primary, secondary and tertiary boronic esters. 1,1-Diboryl alkanes can also engage in base-promoted deborylative cyclization to afford diversified cyclopentane rings with boron motifs attached. This transformation is very appealing because of the prevalence of five-membered rings in natural products. Lastly, it will be showed that geminal bis(boronic) esters can act as an important cornerstone in constructing relatively complicated structures such as natural product Arenolide. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

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En trabajos anteriores [ 1-4] hemos reportado algunas reacciones de generadores - o precursores de nitrenos con sustratos organometálicos, habiendo sido éstos, generalmente, complejos mononucleares del Mo o del W. Los precursores de nitrenos utilizados fueron azidas de ácidos y ésteres carboxílicos así como azidas organometálicas del tipo R 3 MN 3 (M= Si, Ge, Sn), y la mayoría de las reacciones llevadas a cabo fueron de tipo fotolítico (liberación de N 2 a partir de la azida bajo irradiación ultravioleta, con la consiguiente posible formación de nitrenos libres).

archives@tulane.edu / There are three major architectural categories of polymeric materials: linear, branched, and dendritic. Each of these architectures have specific advantages that make them suitable for different applications. However, some of these architectures are inaccessible depending on the monomer system employed. In fact, monomers that can be synthesized into all three of these architectures are extremely rare. This is due to several factors including the lack of a monomer branch point or the poor chemoselectivity of the monomer in use. As a result, there are few monomers, such as 3,5-dihydroxybenzoic acid, that can be synthesized into homopolymers of all three categories. Demonstrations of this level of monomer adaptability are few, but with some recent advancements, another monomer, known as 2,2’-bis(hydroxymethyl)propionic acid (bis-MPA), can be added to this short list of versatile monomers. Bis-MPA is a biocompatible monomer that has been used to synthesize linear, branched, and dendritic materials over the last few decades. Its popularity has grown in academic and industrial settings which has led to numerous publications that show the range of applications it can be used for. However, most of these publications use branched and dendritic bis-MPA architectures. These architectures of bis-MPA have existed for some time and have been well studied. Unlike dendritic and branched bis-MPA, linear bis-MPA has only recently been discovered and detailed (last ~20 years) which has led to the publication of several new applications of bis-MPA materials. While linear bis-MPA has been used to synthesize all three architectures, it is important to note that these linear bis-MPA materials all contain a polycarbonate backbone. This is in stark contrast to traditional bis-MPA materials which contain polyester backbones. Though bis-MPA has been used to synthesize polymeric materials of all three architectures, its important to note that the linear bis-MPA materials published thus far are dissimilar to traditional branched and dendritic bis-MPA. To firmly cement bis-MPA as a versatile monomer, much like 3,5-dihydroxybenzoic acid, a linear polyester bis-MPA material would need to be synthesized. Therefore, the goal of this work is to not only develop a synthetic method for producing linear, polyester bis-MPA but use it to better understand the behavior of dendritic bis-MPA materials and explore its potential application. Herein, linear, polyester bis-MPA was synthesized using a brominated bis-MPA monomer derivative followed by a chain-addition polymerization in mildly basic conditions. This polymerization can take place in a range of solvents and unexpectedly occurs through a chain growth mechanism, which will be discussed. Linear, polyester bis-MPA also proved to be a great analog for traditional bis-MPA dendrimers due to their similar atom economy and repeat unit molecular weight. As such, linear and dendritic bis-MPA analogs were compared in a solution size variation investigation along with poly(caprolactone). These analogs were analyzed using size-measuring techniques including gel permeation chromatography (GPC) and diffusion ordered spectroscopy-nuclear magnetic resonance (DOSY-1H NMR). Finally in this work, a potential application for linear, polyester bis-MPA was explored through the use of triazole chemistry via copper catalyzed azide alkyne cycloaddition (CuAAC). The incorporation of triazole moieties into the linear bis-MPA backbone could be of interest due to the antimicrobial properties of the triazole functional groups. Through the discovery of linear, polyester bis-MPA, bis-MPA can not only be cemented as one of a few highly versatile monomers, but this work opens the door for the exploration of a new class of bis-MPA material. / 1 / Oluwapelumi Kareem

La loi du 6 juin 2006 sur la gestion des déchets radioactifs de haute activité et à vie longue prévoit la recherche de solutions permettant la séparation et la transmutation des radioéléments à vie longue, pour réduire les quantités et la nocivité des déchets radioactifs ultimes. Ces déchets issus du retraitement du combustible nucléaire usé sont actuellement vitrifiés à La Hague. Ainsi, le projet « séparation poussée » vise à compléter le procédé industriel PUREX par le développement de procédés permettant d’extraire les actinides mineurs des raffinats PUREX où se trouvent également des produits de fission constitués principalement de lanthanides, neutrophages. Pour réaliser la séparation poussée, les actinides mineurs des raffinats PUREX doivent être séparés par des molécules spécifiques. Les BTP ou bis-triazinyl-pyridines ont été largement étudiées au CEA pour la séparation actinides(III)/lanthanides(III). Elles complexent sélectivement les actinides, mais l'origine de cette sélectivité n'est pas complètement expliquée : notamment l’influence des groupements (attachés à leur structure) sur la complexation ou la sélectivité reste à démontrer. En outre, elles sont sensibles à l'hydrolyse et à la radiolyse. La première partie du travail présente la synthèse de BTP ou de BTBP, différemment substituées pour améliorer leur résistance face à l'hydrolyse ou à la radiolyse, et une nouvelle famille de ligands polyaromatiques azotés : les BPBT, présentant un enchaînement original de cycles pyridine et triazine, différent de toutes les structures décrites jusqu'à présent dans la littérature. La seconde partie de ce travail est consacrée à l’étude physico-chimique de nouvelles molécules obtenues, en déterminant leurs constantes de protonation et de complexation, pour connaître l’influence des différents groupements sur la complexation et la sélectivité. Enfin, le troisième volet concerne l’étude des propriétés de ces ligands en extraction liquide-liquide, utilisés soit comme extractants lipophiles, soit comme complexants hydrophiles. / In France, the nuclear waste issued from the industrial reprocessing of spent nuclear fuels (by the PUREX process) are currently vitrified at the La Hague plant, waiting for a final disposal in a deep geological repository. The law voted in June 2006 on the management of highly active nuclear waste plans to look for solutions enabling the separation and transmutation of long-lived radionuclides so as to reduce the quantity and noxiousness of the final nuclear waste. To address this issue, the CEA investigates and elaborates advanced separation processes based on specially designed complexing or extracting molecules to selectively extract minor actinides from PUREX raffinates containing fission products like lanthanides, which are neutron scavengers. BTP or bis-triazinyl-pyridines have been extensively studied at the CEA (and in Europe) for actinides(III)/lanthanides(III) separation. They complex actinides(III) selectively. However, they are sensitive to degradation by hydrolysis and radiolysis. Besides, their separation mechanisms are not well understood, especially the influence of their substituting groups on their complexing and extracting properties. The first part of work reports the syntheses of various BTP and BTBP molecules, differently substituted, as well as a new family of polyaromatic nitrogen-contained ligands: BPBT, presenting a pyridine/triazine sequence that has never been reported in the literature. The second part is devoted to the physico-chemistry studies of the synthesized molecules, such as the determination of their protonation and complexation constants to describe the influence of different substituting groups. Finally, the last part outlines solvent extraction studies by using these ligands either like extractants or like compexants.

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Scorpionates are versatile and flexible ligands with a wide range of applications including catalysis, C-H bond activation, formation of new class of materials, and mimicking enzymatic reactions. This is as a result of its steric and electronic properties, and due to the relative ease with which the 3, and 5-positions of the pyrazole ring can be functionalized. In this work, we report the synthesis of a new class of scorpionate ligands known as cyanoscorpionates which can crosslink various metal centers. Thus, bis (4-cyano-3,5-diphenylpyrazolyl)borate BpPh2,4CN was synthesized and fully characterized by 1H NMR and FT-IR. Coordination of bis (4-cyano-3,5-diphenylpyrazolyl)borate BpPh2,4CN to thallium (I) metal was performed and characterized and we are looking to elucidating its molecular structure by X-ray crystallography in future.