Дисертації з теми "Composé diazo"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-17 дисертацій для дослідження на тему "Composé diazo".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Zhao, Chengtao. "Τransitiοn metal-catalyzed diazο cοmpοunds decοmpοsitiοn fοr the catalytic enantiοselective synthesis οf new cyclοprοpanic scaffοlds". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMIR02.
Cyclopropane, a significant organic motif featuring the smallest carbocycle and the highest ring strain, exhibits distinctive properties in comparison to other cycloalkanes. This scaffold is prevalent in natural products and finds extensive applications in medicinal research programs aiming at enhancing the pharmaceutical features of drug candidates. With the continuous advancement of organic and pharmaceutical chemistry, there is a growing interest for versatile molecules incorporating cyclopropane skeleton, particularly those with optical activity or fluorine atom.The first part (chapter II) of this Ph.D. thesis focuses on the use of chiral Ru(II)-Pheox complexes in [2+1] asymmetric cycloaddition, yielding highly functionalized cis and trans cyclopropanes with moderate to high yields (32-97%) and exceptional enantiomeric excess (86-99%). DFT calculations suggest an outer-sphere mechanism. Chapter III introduces a groundbreaking protocol using Ru(II)-Pheox for catalytic synthesis, achieving versatile opportunities for stereocontrolled α,α-difluoroalkyl cyclopropane frameworks with high yields (17-94%) and outstanding diastereo- and enantioselectivity. In chapter IV, we presents optimization studies for enantiomerically pure alkynylcyclopropanes, addressing challenges in enantioselectivity despite successful outcomes in yields and diastereoselectivity with Rh(II)-complexes. Chapter V outlines an efficient methodology for accessing 1,2,3-polysubstituted fluorinated cyclopropanes, using Pd(II)-catalyzed C−C bond formation through C−H bond activation. The method proves tolerant to various electrophiles, offering a practical route for both racemic and enantiomeric fluorinated cyclopropane scaffolds
Pons, Amandine. "Nouvelles méthodes d’accès catalytiques et énantiosélectives aux cyclopropanes fluorés." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR12.
The cyclopropane ring is present in many natural or non-natural bioactive compounds, whose biodisponibility and metabolic stability is increased by its structural rigidity. Besides, the fluorine atom displays singular properties due to its high electronegativity and its small size. This enables to modify the physico-chemical properties of molecules such as acidity, lipophilicity or solubility. As a consequence, fluorinated cyclopropanes represent interesting scaffolds since they combine the properties of cyclopropanes and fluorine atom. In this context, we were interested in the enantioselective synthesis of polyfunctionalized fluorinated cyclopropanes from fluorinated olefins and diazo compounds under rhodium catalysis. For this purpose, two types of diazo compounds were investigated: diacceptor and donor-acceptor. This methodology was further extended to the synthesis of chlorinated and brominated cyclopropanes. To highlight the versatility of these compounds, we then turned our attention to the synthesis of biorelevant targets, and more precisely aminoacids containing a fluorocyclopropane moiety. Indeed, their introduction into peptides could allow to modify their conformation and interactions with biological receptors. In that aim, the synthesis of an analogue of proline containg a fluorocyclopropane was developed. An analogue of leucine containing a fluorocyclopropane was also introduced in the minimum active sequence of neurotensin and shows a good selectivity for the NTS2 receptor. This opens up prospects for the development of new analgesics with less side effects. Finally, we examined the flow synthesis of diazo compounds. Nowadays, diazo compounds are scarcely used in the industry because they exhibit some toxicity, potential explosibility and instability, which restrict their storage. Flow chemistry may constitute an alternative to use them since their synthesis, purification and reaction is continuously made on small quantities at a time and do not require any manipulation from an operator. Hence, the hazards arising from the scale up of the cyclopropanation reaction are highly reduced
Allous, Iyad. "Synthèse de composés diaza-spiraniques analogues d'alcaloïdes cytotoxiques et anticancéreux." Le Havre, 2010. http://www.theses.fr/2010LEHA0004.
Our contribution for the synthesis of spiro-oxindole templates is presented in this memory. For that purpose we have investigated two different approaches employing N-substituted α-bromoacetamides in tandem processes. In the first chapter we have highlighted the importance of chemotherapy in the treatment of disease such as cancer. Among the efficient molecules discovered, the unique structure of the spiro oxindole framework has encouraged the creativity of many researchers. In the second chapter our work was focused on the development of a tandem process to allow the access to oxindoles spiro-fused with succinimide ring. α-Hydroxy-γ-lactams were obtained by regio- and stereoselective reduction of one of both carbonyls of the succinimide moiety and were then engaged in π-cationic cyclization reactions via N-acyliminium species generated by Lewis or Bronsted acids. Thus, complex pentacyclic spiro oxindoles molecules were isolated in good yields and high diastereoselectivities. The third chapter was centered on the application of a new tandem reaction developed in our Laboratory for the synthesis of oxindoles spiro-fused with γ-lactams. The wide variety of reachable structures employing this strategy should allow us to obtain in the near future numerous spiro oxindole frameworks depending on the chemistry involved. Already, Friedel-Crafts and Dieckmann cyclizations were shown to be efficient for the synthesis of elaborated tetra- and pentacyclics spiro oxindole systems, which could be considered as analogous to numerous spiro alkaloids models
Dayoub, Wissam. "Réactivité de rhodiocarbénoi͏̈des issus d'[alpha]-diazo-[beta]-cétophosphonates et d'[alpha] -diazo-[beta]-cétosulfones : synthèse d'éthers d'allyle et de vinyle et de [delta]-lactones, cyclopentén-2-ones ou 3-oxofuranones fonctionnalisées." Lyon 1, 2003. http://www.theses.fr/2003LYO10018.
Lamaa, Diana. "Conception, synthèse et vectorisation de molécules apparentées à l'isocombrétastatine A-4 : Exploration de nouvelles réactivites des composés diazo-précurseurs." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS448.
The thesis reports the synthesis and vectorization of combretastatin A-4 analogues, a natural molecule known for its anti-vascular and cytotoxic properties. Our research work is at the chemistry-biology interface.On the first hand, synthetic methodology studies were performed, indeed coupling reactions between diazo-precursors and haloarenes or amines have been carried out providing new and interesting synthethic tools. These studies led to the synthesis of 2-pyridylalkylamines from pyridotriazole and amines, as well as to the synthesis of the 1,1-diarylethylene compounfs via a green reaction and finally to access to the benzofuran ring through a one-pot fashion reaction ".On the other hand, dual targeting analogs of isocombretastatin A-4 with tubulin and histone deacetylases inhibition properties have been developed. The biological evaluation of these analogs allowed us to identify two lead molecules whose antiproliferative activities on cancer cell lines are in the order of nanomolar. These molecules showed an excellent tubulin polymerization and histone deacetylase 8 inhibitions.Finally, vectorization assays of some isoCA-4 analogs using liposomes or ADCs were performed
Hammoud, Jana. "Evaluation des complexes dirhodium (II) tétraacétate-Carbène-N-Hétérocyclique pour la décomposition de diazoesters et applications en glycochimie Functionalization of GlucoPyranosides at position 5 by 1,5 C–H insertion of Rh(II)-Carbenes: Dramatic influence of the anomeric configuration." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR03.
This work deals with the study of the catalytic properties of Rh₂L₄.NHC complexes towards diazoesters, and their application in the field of glycochemistry. We first developed a reproducible synthetic procedure for the preparation of these organometallic complexes. Furthermore, we have shown that the Rh₂(OAC)₄.IMes complexe was inducing the chemoselective decomposition of diazo esters, depending on their electronic properties. This unprecedented property opened the way to a switchable catalytic system. In the field of glycochemistry, the Rh₂L₄.NHC complexes made possible to improve the experimental conditions for the quaternization reaction of the anomeric position by C-H bond functionalization. Finally, the quaternization of position 5 of pyranosides by 1,5 C-H insertion of a Rh (II) metallo-carbene anchored on the primary position was developed
Bengourina, Chérif. "Synthèse et étude par spectroscopie UV d'agents complexants organophosphores comportant un ou plusieurs motifs 6,9-diaza-1,3-dioxa-2-thiophosphacycloundecane." Lille 1, 1996. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1996/50376-1996-292.pdf.
Keipour, Hoda. "Non-enantioselective and enantioselective synthetic transformations using copper and iron salts for diazo insertion reactions into Si–H and S–H bonds and hydrosilylation reactions of ketones." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/31424.
This thesis describes the development of non-enantioselective and enantioselective synthetic transformations using copper, iron, and zinc salts as environmentally benign catalysts for diazo insertion reactions into the Si–H and S–H bonds and hydrosilylation reactions of ketones. Non-enantioselective and enantioselective copper and iron-catalyzed metal carbene insertion reactions of α-diazoesters into Si–H and S–H bonds are described. We successfully developed an efficient copper and iron-catalyzed protocol for the metal carbene insertion reaction of α-diazoesters into Si–H and S–H bonds. By using [(MeCN)4Cu]PF6 and Fe(OTf)2, a wide range of α-silylesters were synthesized in good to excellent yields (up to 98%). These catalysts have been shown to be efficient for metal carbene insertion into S–H bond in high yields (up to 90%) as well. Excellet results have been obtained for iron-catalyzed carbene insertion reactions of α-diazoesters into Si–H bond using DMC as a green solvent instead of CH2Cl2. Several chiral diamine ligands were tested to develop a highly enantioselective metal carbene insertion reaction into the Si–H bond using the inexpensive copper salt [(MeCN)4Cu]PF6 as catalyst. Excellent yield and enantioselectivity (85% yield, 99:1 er) were obtained when the ligands containing a (R, R)- diaminocyclohexane core and mesityl groups were used. This is the very good example of highly enantioselective Si–H bond insertion reactions using aryldiazoacetates and inexpensive silane sources compare to others and easy-to-synthesize chiral diamine ligands that have been used for the first time for enantioselective Si–H bond insertion reaction. We have found that the readily available chiral diamines are also efficient ligands for the reduction of aryl ketones using Zn(OAc)2 as catalyst. The desired alcohols were obtained in high yields and very good enantiomeric ratios (up to 99% yields, up to 99:1 er). We also obtained good results for the hydrosilylation of p-phenyltrifluoroacetophenone using a bipybox-iPr/Fe(OAc)2 system (85% yield, 80:20 er). Based on the information in the literature, there are just a few examples on asymmetric hydrosilylation of pphenyltrifluoroacetophenone using ZnEt2 with very low enantioselectivities.
Huang, Weisheng. "Catalytic asymmetric cyclopropanation and oxidation of tri-, di- and monofluoromethyl styrenes Rhodium catalysed enantioselective synthesis of mono-(halo)-methyl-cyclopropanes Catalytic enantioselective synthesis of highly functionalized difluoromethylated cyclopropanes General catalytic enantioselective access to monohalomethyl and trifluoromethyl cyclopropanes Catalytic asymmetric synthesis of α,α-difluoromethylated and α-fluoromethylated tertiary alcohols". Thesis, Normandie, 2019. http://www.theses.fr/2019NORMIR25.
This thesis presents the enantioselective synthesis of functionalized trifluoromethyl, difluoromethyl and monohalomethyl cyclopropanes based on the cyclopropanation reaction of alkenes bearing various fluorinated groups. In addition, the synthesis of enantioenriched fluorinated tertiary alcohols resulting from the dihydroxylation of fluorinated olefins is discussed. This thesis is divided into three chapters. In the first chapter, we reported the first example of catalytic asymmetric synthesis of difluoromethyl cyclopropanes, which is achieved by using Rh₂((S)-BTPCP)₄ as a catalyst to perform the cyclopropanation reaction of α,α-difluoromethyl olefins with donor-acceptor diazo compounds and di-acceptor diazo compounds. This methodology allows the access to a broad range of cyclopropanes in high yields with excellent diastereo- and enantioselectivities (up to >20:1 and up to 99% ee). In the second chapter, a practical and efficient asymmetric synthesis of trifluoromethyl cyclopropane derivatives was described and a series of functionalized cyclopropanes were obtained in excellent diastereoselectivities with excellent enantioselectivities (up to >20:1 and 99% ee). These investigations also extended to the synthesis of highly enantioselective monohalomethyl cyclopropanes. In the third chapter, the initial propose aimed at exploring the asymmetric epoxidation of α,α-difluoromethyl styrenes. The reaction was performed in the presence of a metal-catalyst or an organic catalyst, unfortunately, none of the result was positive. Therefore, we turned our attention to the asymmetric synthesis of α,α difluoromethylated tertiary alcohols. To this propose, the use of commercially available reagents AD-mix-α and AD-mix-β as the best catalysts, allowed the reaction with α,α-difluoromethyl styrenes to construct the corresponding α,α-difluoromethylated tertiary alcohols in good to high yields with excellent enantioselectivities (up to 99% ee). In addition, this transformation could be applied to a broad range of substrates, including variety of α,α-difluoromethyl styrenes, α-monofluoromethyl styrenes, β-difluoromethyl styrene and β-trifluoromethyl styrene
Menu, Marie-Joëlle. "Nouveaux reactifs dans la chimie des complexes du rhodium, du chrome et du tungstene : les anions diazo rc(n::(2))**(-)." Toulouse 3, 1988. http://www.theses.fr/1988TOU30068.
Legentil, Laurent. "Etude d'aza-analogues des alcaloïdes marins de type pyrroloquinoline, wakayine et tsitsikammamines à activité antitumoral potentielle : approche vers la synthèse totale des produits naturels." Toulouse 3, 2004. http://www.theses.fr/2004TOU30283.
The marine alkaloids wakayin and tsitsikammamines A and B belong to the 1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinolines family. They both possess cytotoxic properties which seem related to inhibition of topoisomérases I and II. Two series of aza-analogues of these compounds (pyrazoloquinolines and pyrroloquinolines analogues) have been investigated. The pyrazole ring was obtained on the basis of a [3+2] dipolar cycloaddition reaction between various quinones and diazo species (alkyls or aryls). The iminoquinone moiety was then formed through an intramolecular cyclisation. The different compounds have been evaluated for both in vitro cytotoxic activity against 5 dictinct cancer cell lines and topoisomérases I and II inhibition. Most of the compounds inhibit one or the two enzymes whereas only few of them exhibit cytotoxic activity with IC50 values of micromolar order. The total synthesis of the natural alkaloids has also been studied. The retrosynthetic pathway was based on a Michael addition between 3-éthylamine-indoledione and different protected β-cétoamines. An original analogue of tsitsikammamines has been obtained
Morel-Desrosiers, Nicole. "Contribution a la thermodynamique des solutions de cryptates alcalins et alcalino-terreux dans l'eau et le methanol." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2E374.
Allouche, Emmanuelle. "Fonctionnalisation d'halocyclopropanes et préparation de composés diazoïques semi- et non-stabilisés pour la synthèse de cyclopropanes polysubstitués." Thèse, 2019. http://hdl.handle.net/1866/23398.
The cyclopropane moiety is present in a large number of bioactive molecules as its incorporation usually improves their physicochemical properties. As a result, the development of new methodologies allowing the synthesis of various substituted cyclopropanes have become of significant interest. In order to access stereoenriched 1,2,3-trisubstituted cyclopropanes, we first developed a Suzuki-Miyaura cross-coupling of 2,3-disubstituted halocyclopropanes synthesized in the group using a chiral dioxaborolane ligand. Mild and highly reproducible reaction conditions were developed, especially thanks to the synthesis of a Buchwald type pre-catalyst. The next chapters were devoted to the synthesis of substituted cyclopropanes using diazo compounds bearing the groups to introduce. Semi-stabilized diazoalkanes (bearing π-system-containing groups such as aryl or alkene moieties) were first employed. The use of an iron porphyrin allowed the cyclopropanation of aryldiazomethanes generated in situ from 2-nosylhydrazones under mild conditions, enabling a broader scope of semi-stabilized diazo compounds that can be used in cyclopropanation reactions. Then, we investigated the cyclopropanation of dialkyldiazoalkanes generated in situ from arylsulfonylhydrazones. Gem-dimethyl cyclopropanes, motifs of particular interest in medicinal chemistry, were synthesized under metal-free conditions. However, high temperatures were needed to decompose the diazo precursors. Because of these harsh reaction conditions, we moved to another strategy enabling the synthesis of non-stabilized diazo compounds. We envisioned the oxidation of free hydrazones, being a more atom economical process that typically requires lower temperatures. After the completion of a project initiated by other group members employing stoichiometric amounts of a metallic reagent, we investigated the use of an organic oxidant. Iodosylbenzene allowed the generation of numerous aliphatic diazo compounds and was compatible with the in situ [3+2] cycloaddition of various Michael acceptors. Conversion of the 1-pyrazolines into the corresponding cyclopropanes was not always spontaneous under these reaction conditions, and therefore a photolysis process using continuous flow was developed in order to induce the ring contractions. Unnatural amino acids and gem-dimethyl cyclopropanes were synthesized in high yields using methodology. Immobilizing the iodosylbenzene in a packed bed reactor using a continuous flow set up allowed us to rapidly generate clean solutions of phenyldiazomethane. However, the production of non-stabilized diazo compounds using this process turned out to be more complicated due to numerous incompatibilities. Finally, the syntheses of amino-, alkoxy- or aryloxycyclopropanes were attempted by generating heteroatom-substituted diazo compounds from the corresponding free hydrazones. An aminocyclopropane was obtained during the initial investigation of this reaction. Although in low yield, this result showed the feasibility of each and every step.
Benoit, Guillaume. "Synthèse et fonctionnalisation de borocyclopropanes et développement d’un procédé de synthèse de diazoalcanes non-stabilisés en utilisant la technologie en débit continu." Thèse, 2017. http://hdl.handle.net/1866/20438.
Audubert, Clément. "Méthylénation et diazotisation en chimie en flux continu." Thèse, 2018. http://hdl.handle.net/1866/21580.
Paquet, Valérie. "Développement et application d'une nouvelle méthodologie de méthylénation catalytique de composés carbonylés." Thèse, 2004. http://hdl.handle.net/1866/16738.
Lindsay, Vincent. "Synthèse stéréosélective de dérivés cyclopropaniques di-accepteurs par catalyse avec des complexes de rhodium(II)." Thèse, 2012. http://hdl.handle.net/1866/8976.
Di-acceptor cyclopropane derivatives are valuable synthetic intermediates in the preparation of complex molecular structures, with applications in several fields of chemistry. During this work, we investigated the synthesis of these units in enantioenriched form via the Rh(II)-catalyzed cyclopropanation of alkenes using di-acceptor diazo compounds as substrates. Following the initial development of a method for the catalytic asymmetric cyclopropanation of alkenes using nitro diazoketones, many experimental studies on the mechanism of stereoinduction in this reaction were performed. We were able to identify the p-methoxyphenylketone group of the substrate and catalyst Rh2(S-TCPTTL)4 as a key combination for the obtention of high diastereoselectivities and enantiomeric excesses. This led to the development of two distinct stereoselective cyclopropanation methods, using either an cyano diazoketone or a keto diazoester. We demonstrated the utility of the enantioenriched cyclopropane derivatives obtained by these three methods in a variety of synthetic manipulations, including the nucleophilic addition of amines and cuprates, the formal cycloaddition with an aldehyde, and the synthesis of biologically relevant cyclopropane derivatives. A thorough structural study of chiral Rh(II) complexes allowed us to determine the factors responsible for their enantioinduction ability in our reaction system, which has enormous implications in other metal-carbene reactions using these catalysts. The unveiling of an unexpected conformation called 'All-up', and the presence of stabilizing interactions controlling the rigidity of this arrangement have been crucial in our understanding of the mechanism. As part of this investigation, we developed a general method for the synthesis of heteroleptic Rh(II) complexes, thus multiplying the number of catalysts available in the development of new stereoselective reactions, and allowing us to conduct a more detailed structural study. Moreover, we have developed a particularly efficient method for the synthesis of another type of di-acceptor cyclopropane derivative via Rh(II) catalysis, cyanocyclopropylphosphonates. The highly enantioenriched products obtained in this transformation are interesting substrates for tandem reactions of nucleophilic addition / olefination of carbonyl compounds, and are precursors of useful molecules in medicinal chemistry, such as aminocyclopropylphosphonic acids.