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The series Topics in Heterocyclic Chemistry presents critical reviews on present and future trends in the research of heterocyclic compounds. Overall the scope is to cover topics dealing with all areas within heterocyclic chemistry, both experimental and theoretical, of interest to the general heterocyclic chemistry community. The series consists of topic related volumes edited by renowned editors with contributions of experts in the field. All chapters from Topics in Heterocyclic Chemistry are published Online First with an individual DOI. In references, Topics in Heterocyclic Chemistry is abbreviated as Top Heterocycl Chem and cited as a journal.

Chemistry. --- Bioorganic chemistry. --- Carbohydrates. --- Medicinal chemistry. --- Bioorganic Chemistry. --- Carbohydrate Chemistry. --- Medicinal Chemistry. --- Chemistry, Medical and pharmaceutical --- Chemistry, Pharmaceutical --- Drug chemistry --- Drugs --- Medical chemistry --- Medicinal chemistry --- Pharmacochemistry --- Carbs (Carbohydrates) --- Bio-organic chemistry --- Biological organic chemistry --- Chemistry --- Biochemistry. --- Biomolecules --- Organic compounds --- Glycomics --- Biochemistry --- Chemistry, Organic --- Biological chemistry --- Chemical composition of organisms --- Organisms --- Physiological chemistry --- Biology --- Medical sciences --- Composition

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Ces dernières années, l'évolution au sein de l’industrie chimique a conduit à l'interdiction de réactions chimiques considérablement dangereuses afin d'éviter des accidents graves, en particulier pour les procédés à grande échelle. L'émergence actuelle des technologies relatives à la chimie en flux continu a complètement redéfini la façon dont sont abordés ce type de procédures et a permis la renaissance de réactions autrefois considérées comme trop dangereuses en permettant le développement de procédés plus sûrs. Dans le cadre de ce travail, nous nous sommes attaqués à la valorisation de divers dérivés (poly)alcools avec des réactifs ou des intermédiaires particulièrement sensibles, corrosifs et/ou toxiques en mettant en œuvre, au sein des procédés, des outils et des protocoles plus sûrs qui permettent la production efficace et rapide de divers produits finaux à haute valeur ajoutée. Deux thèmes principaux sont abordés ici, à savoir la valorisation de molécules biosourcées et l’emploi d’espèces organophosphorées (et eventuellement chlorées). Les différents programmes de recherche portant sur ces deux thèmes ont permis de produire en toute sécurité des médicaments cardiovasculaires et chimiothérapeutiques essentiels, des polymères ayant des applications biomédicales et ignifuges et d’importants ligands employés en catalyse asymétrique en utilisant des réacteurs à flux continu.

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La tomographie par émission de positons est une méthode de choix pour détecter les maladies comme les tumeurs à un stade précoce de leur développement. Cette technique d’imagerie médicale requiert l’utilisation de radiotraceurs résistants in vivo. Dans cette optique, les sels d’iodonium ont été utilisés comme précurseurs pour le marquage au 18F de cycles aromatiques, plus résistants in vivo que leurs homologues aliphatiques. Les objectifs de ce mémoire étaient d’automatiser, sur une plateforme FASTlab™, le marquage au 18F de composés aromatiques en chimie verte et ensuite d’adapter la synthèse sur un microréacteur. Chaque étape de l’automatisation a été travaillée dans des solvants de classe 3 de la pharmacopée européenne, sans utiliser de base, d’agent de transfert de phase ni de catalyseur toxiques : 1 - l’élution des [18F]F- piégés sur une cartouche a été optimisée avec un faible volume d’une solution du précurseur dans un mélange EtOH/DMSO, 2 – l’évaporation de l’EtOH a été optimisée, 3 - le marquage au 18F des iodoniums a été réalisé dans le DMSO. À titre de comparaison, un ammonium quaternaire a également été marqué dans des conditions vertes similaires et a permis d’atteindre des rendements corrigés de presque 60%.

iodonium --- chimie verte --- marquage --- 18F --- cycle aromatique --- Physique, chimie, mathématiques & sciences de la terre > Chimie

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Polyurethanes are a very important class of materials which finds applications in gasket sealers, cushioning and medical implants. The industrial synthesis of polyurethanes involve the use of phosgene and isocyanate compounds, noxious substances, which due to changes in REACH regulations tends to prohibition in the near future. An alternative for the synthesis of polyurethanes resides in the step growth polymerization of bis-cyclic carbonates with diamines. The cyclic carbonates can be prepared by the coupling of carbondioxide with epoxides, or diols. Polymerisation of the carbonates thus prepared, is non regioselective, and affords polyurethanes with primary or secondary alcohols, which favors side reactions and limits the molar mass of the polymer. A solution to this problem is the use of alpha alkylidene cyclic carbonates prepared by coupling CO2 with propargylic alcohols. Due to the high thermodynamic stability of CO2 a catalyst is required for the coupling reaction. Transition metal-based complexes, organic bases (guanidine, amidine, phosphine) and N-heterocyclic carbenes or olefins, have been proposed as catalysts. However they generally present sufficient activity at high pressure and/or temperature or require a high catalyst loading. Additionally some of them are toxic and/or sensitive to hydrolysis or oxidation. The objectives of this work was to develop new, efficient, and highly selective organo catalysts for the synthesis of cyclic carbonate monomers, and to prepare new non isocyanate polyurethanes using the monomers. We developed new, cheap, efficient organocatalyst, for the synthesis of a new bis-alpha alkylidene cyclic carbonate monomer. The bis-alpha alkilidene cyclic carbonate monomer was copolymerized with a diamine to afford a new regioregular poly(oxo-urethane).

CO2, cyclic carbonates, organocatalysts, poly(oxo-urethanes) --- Physique, chimie, mathématiques & sciences de la terre > Chimie

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Nitroso species and their wide variety are known for decades and are involved in numerous applications such as hetero Diels-Alder reactions or electrophilic aminations on α-ketones. However, they intrinsic poor stability, toxicity and their relative hazardous profile tuned down their potential use at an industrial-scale. In a conventional batch reactor, these reactions are relatively long (20-45 min) and the conversions associated are uncomplete.
In this work, safe and efficient continuous-flow procedures for the preparation of α-chloro-nitroso species from aqueous sodium hypochlorite and oximes were developed. The conditions were first developed in a microfluidic setup, and next transposed to an industrial mesofluidic flow reactor. The lab-scale continuous-flow setup developed in this project affords complete conversion within minutes for different kinds of starting oximes (aliphatic and alicyclic, including chiral substrates). The process is very safe, and in-line IR analysis complements the control over the process conditions. The setup is amenable to the generation of libraries of α-chloro-nitroso and sustains productivities of up to 6 mL min-1, delivering ready-to-use α-chloro-nitroso species. 
The scope of the method was next assessed with a concrete application of α-chloro-nitroso species toward the synthesis of pharmacological active norephedrine. The optimized strategy toward norephedrine from propiophenone involved four steps with an overall isolated yield of 53%. Besides, several α-chloro-nitroso classes (aliphatic, alicyclic and chiral) were tested. In the last part of this work, we assessed the full development of a continuous-flow process toward norephedrine from a propiophenone derivative. Encouraging preliminary data was obtained.

Nitroso --- α-chloro-nitroso --- Hetero Diels-Alder --- Electrophilic amination --- Continuous-Flow processes --- Physique, chimie, mathématiques & sciences de la terre > Chimie