Dissertations / Theses on the topic 'Réaction photochimique en tandem'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Réaction photochimique en tandem.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Yu, Xiaodan. "New functionalized alkylidenecyclobutanes : multicomponent synthesis and applications." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASF034.
Full textCyclobutane derivatives have become increasingly important as molecular building blocks because of their inherent ring strain that facilitates the selective modification of their structures for strategic used in organic synthesis. Cyclobutane rings also appear in the molecular structures of a wide panel of natural and synthetic molecules that display interesting biological activities. Within this large family, alkylidenecyclobutane subunits are encountered in natural products, such as providencin, and they exhibit enhanced reactivity providing access to complex molecular structures, including enlarged ring and highly functionalized cyclobutane derivatives. In our laboratory, we recently developed an efficient synthesis of functionalized cyclobutenes through a domino photochemical reaction starting from cyclopent-2-enones and ethylene. Based on this study, we first explored a straight-forward transformation of functionalized cyclobutenes into alkylidenecyclobutanes. We then combined both sequences in a domino-multicomponent process. This was accomplished in a single protocol, comprising a tandem photochemical [2+2]-cycloaddition / Norrish-I / γ-H transfer reaction followed by an acetal-protection and an allylic substitution reaction. Additionally, the intramolecular version of these reactions allowed the synthesis of complex fused-bicyclic alkylidenecyclobutanes. Finally, the post-funtionalization of selected alkylidenecyclobutanes was studied, aiming to prepare novel fused tricyclic compounds through a intramolecular [2+2] photochemical process
Peyrane, Frédéric. "Origine des mutations tandem CC vers TT dans les cancers de la peau : approche synthétique des adduits cyclobutaniques de cytosine." Paris 11, 2004. http://www.theses.fr/2004PA112092.
Full textThe cyclobutane photoproducts (CPD) of cytosine are natural damages of DNA and are potentially involved in skin carcinogenesis. Their precise mutagenic effect has however not been fully assessed because of instability problems. We have developped three approaches for the synthesis of this photoproduct that could be incorporated into a shuttle vector for mutagenicity studies. The photosensitized irradiation of a protected dCpdC dinucleotide (path 1) failed, because of a lack of reactivity. The photolysis of a tetrazolo[1,5-c]pyrimidin-2-one dinucleotide analogue (path 2) led to the isolation of Iwo CPOs (cis-syn 41%, trans-syn Il 16%). Moreover it obviates the deamination process. Unfortunately, the subsequent reduction of the tetrazole ring, regenerating the cytosine CPD adduct, could not be accomplished. A thiation/amination sequence of dUpdU CPD compounds (path 3) was then investigated. Despite the conversion of the silylated 2'-deoxy-5,6-dihydrouridine, used as a model, into its cytosine analogue, the application of this strategy to a dinucleotide was unsuccessful, because of the sensitivity of the phosphotriester group under the reaction conditions used
Laurent, Michel. "Comportement de molécules chromophores dans des mésophases nématiques lyotropes et application à l'analyse d'une réaction photochimique." Paris 11, 1987. http://www.theses.fr/1987PA112005.
Full textGodineau, Edouard. "Synthèse de Pipéridinones fonctionnalisées par cascade radicalaire-ionique et réaction multicomposants." Bordeaux 1, 2007. http://www.theses.fr/2007BOR13502.
Full textThe piperidine framework is ubiquitous in Nature and found in a wide number of biologically active natural products. Piperidinone analogues are often encountered as key elements in the retrosynthetic plans of such targets. We first have developed a new stereoselective access to fused bicyclic piperidinones. Our approach relies on a cascade reaction which is on a mechanistic standpoint, built upon the combination of radical and ionic processes. We next turned toward the development of an even more convergent strategy. We indeed devised a one-pot protocol for the synthesis of functionalized piperidinones by assembly of three independent components. A sequential four component variant was also discovered, allowing for the synthesis of piperidinones bearing up to three stereogenic centers with total stereocontrol
Marin, Lucile. "Réaction d’aza-Piancatelli : nouvelles applications, version diastéréosélective et utilisation en synthèse totale." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS206.
Full textDue to their various functionalizable sites, cyclopentenones are very useful intermediates for the synthesis of natural products of therapeutic value. In particular, 4-aminocyclopentenones enable the access to the aminocyclopentitol frameworks, which are present in a variety of bioactive molecules such as peramivir, pactamycin, or trehazolin. One of the most efficient methods to access 4-aminocyclopentenones is the aza-Piancatelli reaction. It is based on the rearrangement of 2-furylcarbinols in the presence of a nitrogen nucleophile following a mechanism involving a 4π-conrotatory electrocyclization. In our laboratory, a simple catalytic system using a calcium complex combined with an ammonium salt was developed to gain access to these compounds. This method has many advantages : it is effective (yields up to 98%), fast (15 to 30 minutes), it requires only 1 mol% of catalyst under pratical conditions (undistilled solvents without an inert atmosphere) on a large scale (multi-gram). In this context, we sought to extend the scope of this reaction by designing more complex 2-furylcarbinols in order to directly access skeletons of bioactive compounds. In particular, we focused on the total synthesis of jogyamycin. In addition, we achieved the total synthesis of bruceollin D with an overall yield of 16% over five steps. We also developed a new reaction sequence involving an aza-Piancatelli reaction followed by a hydroamination reaction promoted by a copper salt. This sequence provides a wide range of highly functionalized cyclopenta[b]pyrroles from readily-available 2-furylcarbinols substituted by an alkyne moiety. Following this method, 42 cyclopenta[b]pyrroles were obtained with yields up to 98%. An original feature of this transformation is related to the use of ortho-substituted anilines. Indeed, in this case, atropisomers with a diastereomeric excess superior to 20:1 could be obtained accompanied by the creation of an chiral N-C axis during the hydroamination step. To date, no other example of atropodiastereoselective synthesis of cyclopenta[b]pyrroles has been reported. During our investigations on the scope of the reaction, we noticed that cyclopenta[b]pyrroles underwent a rearrangement into cyclopenta[b]pyrrolines, following a dearomatization when hexafluoroisopropanol was used as solvent. This transformation led to 13 cyclopenta[b]pyrrolines with yields ranging from 44% to 73%. We also investigated the functionalization of the cyclopenta[b]pyrrole motif to illustrate the synthetic utility of our methodology, notably by combining this reaction sequence with a Friedel-Crafts reaction. One of the objectives of this Ph.D. was the development of an enantioselective version of the reaction. After the recent publication of three papers using chiral phosphoric acids as catalysts, we devised another approach for the asymmetric synthesis of 4-aminocyclopentenones, relying on the use of a chiral auxiliary (chiral sulfoxide) in collaboration with Dr. Wencel-Delord and Pr. Colobert (University of Strasbourg). Thus, we were able to provide the corresponding 4-aminocyclopentenones with excellent yields and diastereoselectivity
Favre, Annaïck. "Applications de la réaction tandem hétéro Diels-Alder / Allylboration à la synthèse de produits naturels." Rennes 1, 2007. http://www.theses.fr/2007REN1S120.
Full textHe utilisation of an hetero Diels-Alder/allylboration asymmetric tandem reaction for the synthesis of several natural products, has been studied. It has been shown that the hydroxyalkylated dihydropyran unit, obtained frome this reaction, opens the access to different molecules from the Styryllactones’ family. It has been shown that the use of the paraformaldehyde during the process, makes possible the synthesis of natural products bearing a double bond adjacent to the heteroatom of the cycle. This tandem reaction has also been employed for the synthesis of the laulimalide’s C₁₅-C₂₇ fragment and three analogs. Finally, some tests have been managed for the second C₁-C₁₄ fragment’s synthesis
Moussa, Saber. "Réactions tandem de type aza-MIRC et ions N-acyliminiums : accès rapide et stéréocontrôlé à des nouvelles structures aza-cycliques." Le Havre, 2010. http://www.theses.fr/2010LEHA0009.
Full textThis report presents a new method of the preparation of a new class of highly functionalized N, O – acétals and the study of their ability to react towards catalytic intra – and intermolecular α-amidoalkylation reactions. In a first chapter, we described some methods of synthesis of the precursors of N–acyliminiums ions and their various activation pathways. In the second chapter we elaborated the synthesis of functionalized 5-alkoxypyrrolidinones as precursors of N–acyliminiums species according to a new aza-MIRC tandem process with involves commercial diester-, cyanoester-, and dicyano alkoxymethylenes and various N-substitued α-bromoacetamides as dipole-[1,3]. A first application of the N,O-acetalic moiety in previously synhesized lactams is described in the third chapter involving intramolecular Friedel-Crafts reactions. This study, conducted from N-arylethyl substituted γ-lactams, and leading and a simple and fast way to tricyclic compounds of biological interest. These results allowed us to point out the positive effects of both arms ester in α-position of the reaction site. Explained essentially by an assistance to the generation of the N-acyliminium ion and also by an increase of its reactivity potential by the formation of a pseudocyclic intermediate resulting from an anchimeric assistance. The fourth chapter was the object of a complementary study that led previously by the investigation of the intermolecular approach of the α-amidoalkylation reaction. The reactivity results showed a perfect analogy with those of the intramolecular study. The synthetic application of thes adducts was demonstrated by some examples of synthesis of bicycles compouds by metathesis
Coudanne, Isabelle. "Réactions "tandem" palladocatalysées : nouvelles voies d'accès à des systèmes polycycliques fonctionnalisés." Lyon 1, 1997. http://www.theses.fr/1997LYO10348.
Full textLescarbeau, André. "Étude de la réaction de Cope et d'oxy-Cope en tandem pour la formation de squelettes carbonés." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0031/MQ67306.pdf.
Full textMac, Dinh Hung. "Nouveaux développements de la réaction tandem isomérisation-aldolisation intramoléculaire à partir d'alcools allyliques et/ou de lactols." Rennes 1, 2009. http://www.theses.fr/2009REN1S111.
Full textThis thesis work is an extension of our group's research programme on the tandem intramolecular isomerization-aldolization reaction from allylic alcohols and/or lactols. The first chapter deals with the application of this reaction towards the enantioselective total synthesis of bioactive natural compounds, the Gabosines. In the second chapter, we describe an original synthesis of new iminosugars with a polyhydroxypiperidine skeleton. This family of compounds is particularly interesting from a biological point of view because they are glycosidases inhibitors and, as such, they are developed against various diseases (cancer, diabetes, etc. . . ). The final chapter concerns the first extension of this reaction to a bicyclic system, leading to new fonctionalized bicyclo [3. 2. 1] octane derivatives. In this particular case, we observed a total stereocontrol for the tandem reaction and this result could be rationalized by the DFT calculation of the transitions states
Rizzotto, Denis. "Synthèse de quinanes fonctionnalisés par réaction tandem rétro-aldol/cycloaddition [3+2] entre cétones méthylènecyclopropaniques et allysilanes." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX30029.
Full textSakri, El-Bahri. "Etude cinétique de la polymérisation photochimique du méthacrylate de méthyle en présence d'agents complexant organochloroaluminiques." Paris 6, 1986. http://www.theses.fr/1986PA066140.
Full textBourcet, Emmanuel. "Application des réactions de métathèse en synthèse totale : approche synthètique vers les aurisides." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00694389.
Full textChapellas, Fabien. "Etude de cycloadditions tandem cascade [4+2] / [3+2] désaromatisante à partir de nitroarènes." Rouen, 2011. http://www.theses.fr/2011ROUES026.
Full textAminated heterocycles represent one of the most important structural classes of interest for the pharmaceutical research. More than 90% of the compounds in the field bear at least one of these “privileged-structures”. Among the oldest methods to get access to aminated molecules, those relying on the chemistry of nitro derivatives play a particularly important role. We thus have developed a multicomponent methodology in which, under hyperbaric activation, a nitroarene derivative first reacts as an inverse electron demand heterodiene with an electroenriched dienophile, to generate an intermediate nitronate that undergoes a subsequent [3+2] cycloaddition, leading to a nitrosoketal derivative. Such compounds are useful synthetic scaffolds, giving an easy access to nitrogenated motifs, after cleavage of the N-O bonds, for instance. We have shown that this domino [4+2]/[3+2] cycloaddition process can be applied to a wide panel of nitroaromatic substrates including indoles, thiophenes, benzofurans, furans, imidazoles, naphtalenes, and even benzene, for instance. The aminated compounds generated by this methodology all bear a tetrasubstituted center adjacent to the nitrogen atom. Such structural motifs are of difficult access by other synthetic methods. Our method thus bears the advantage of involving simple starting materials to lead, in two or three synthetic steps only, to dearomatized aminated polycycles
Rondot, Christophe. "Méthodologies de synthèse diastéréosélectives d'ortho-1,2-diaminoalkylphénols, vers la synthèse totale des bioxalomycines - réaction tandem de N-arylation / Heck compétitive." Phd thesis, Ecole Polytechnique X, 2005. http://pastel.archives-ouvertes.fr/pastel-00001537.
Full textRégnier, Noémie. "Design et synthèse d’hétérocycles fusionnés polysubstitués par réaction multicomposante de Ugi en tandem pour le développement d’agents antimicrobiens et antinéoplasiques." Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69369.
Full textBenzodiazepines and quinoxalines are very important structures in medicinal chemistry and they can be foundin a great number of marketed and clinically important drugs. In addition to their wide spectrum of biological activities and good pharmacokinetic properties, these benzo-fused heterocycles are able to mimic several types of peptide motifs and protein secondary structures. These characteristics make them very attracting scaffolds in the pharmaceutical industry for the development of new therapeutic agents.The first part of the thesis describes the development of a synthetic route for polysubstituted 3,4-dihydroquinoxalin-2-ones using the Ugi-deprotection-cyclization (UDC) strategy. This convenient and efficient method involves a Ugi multicomponent reaction followed by simultaneous deprotection and cyclization byaromatic nucleophilic substitution. A first study of the multicomponent reaction showed that preformation of the imine was necessary to avoid the presence of an important side product resulting from the Passerini multicomponent reaction. Once this first step optimized, the deprotection and cyclization were also analyzed to identify the best reaction conditions. Finally, the optimal conditions identified for the different steps were used for the production of a chemical library of 3,4-dihydroquinoxalin-2-ones which will be involved in future biological tests. The second part of the thesis describes the transfer on solid support of the 1,4-benzodiazepin-3-one synthesis by UDC. Different resins were tested and the results showed that the Ugi reaction and deproctection worked very well on most of them. However, the cyclization step was much more difficult. Following the evaluation of several conditions in solution for the cyclization, the use of the best conditions on solid support allowed the preparation of a 1,4-benzodiazepin-3-one derivative. There is still optimization to do for the cyclization step butthis work pave the way for the synthesis of benzodiazepines on solid support by UDC and the preparation of polysubstituted 1,4-benzodiazepin-3-one libraries.
Cros, Fanny. "Application des processus de métathèse à la synthèse de produits naturels marins." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10103.
Full textThe metathesis realized an important development during the last few years and the Nobelprize given to the chemists Yves Chauvin, Robert H. Grubbs et Richard R. Schrock came toreward this work. This reaction has been involved for the synthesis of natural molecules of marine origin. Thiocyanatines A and B, isolated in 2001, have been so prepared by using the reaction of cross metathesis. This is the first example of metathesis with the presence ofthiocyanates groups. Moreover, these two syntheses are using the microwave technology. Largazole, isolated in 2008, is a very important synthetic target because of its anticancerous activity. This manuscript is explaining the synthesis of one part of this molecule but it also provides a methodological study for the formation of thiazoles motives by microwave. Then,Rugulactone, isolated in 2009, has been prepared with a tandem strategy of ring clossing metathesis / cross metathesis and this one has been applied to the synthetis of analogues
Bendaikha, Tahar. "Photopolymérisation réticulante de macromères multifonctionnels : comportement photochimique de réseaux polyacryliques tridimensionnels." Mulhouse, 1986. http://www.theses.fr/1986MULH0016.
Full textNassar, Hardy Luma. "Tandem reactions using multi-task catalysts." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14317/document.
Full textThe development of clean chemistry and therefore sustainable is one of the major challenges of the 21st century in industrialized countries. Being in the heart of many discoveries in various scientific fields ranging from physics to medicine, the chemical sciences must play a central role in solving a number of environmental problems we face. My thesis work is part of this problem through the development of synthetic methodologies involving several transformations in the same reactor. We have developed the reaction sequences called HRC (for Heck-Reduction-cyclization) building on the multi-task of a palladium catalyst. This work allowed us to prepare a variety of functionalized heterocycles or compounds from which we can cite the oxindole, the indanones, or the naphthoxindoles. This work has resulted for the time four publications in peer-reviewed journals
Masse, François. "Cinétique de photolyse d’oxydes d’azote sous rayonnement UV." Mémoire, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9795.
Full textHeudron-Jourdan, Hélène. "Doubles réactions de Petasis : Nouveaux processus tandem séquentiel et cascade en solution et sur phase solide." Rouen, 2007. http://www.theses.fr/2007ROUES010.
Full textThis work focuses on the development of new methodologies which consists in performing one-pot double Petasis reactions. This reaction is a multi-component process (M-CR) of high exploratory power that yields diversified amines from amines, carbonyl compounds and organoboron derivatives. Firstly, double Petasis tandem were processes were sequentially carried out with boronic acids. Complex molecules featuring 5 sites of diversity were synthesized with good yields and good diastereometric excesses, thanks to the use of HFIP as cosolvent. Depending on the carbonyl substrate, a,a’-aminodiesters or polysubstituted morpholinones were obtained, after esterification. Secondly, the reactions were developed as cascade processes. To achieve this, boronic esters were considered and used. The development of 3 new efficient protocols (methanol or HFIP at room temperature or under microwaves irradiations) broadened the use of these species in general Petasis reactions. Chiral boronates yielded no significant improvement of diasteroselectivity. The cascade process or 5-CR was then carried out by introducing both boronic acid and ester. Mixtures of products were obtained, the result of a competitive transboroesterification process. A study on boronate reactivity pointed the finger at boronic acids, formed in situ by hydrolysis of esters, as the reacting species. Finally, the methodology developed in the first part was transfered to solid phase chemistry with the goal of producing libraries with the help of automated synthesizers. Conditions allowing either the mono or the double Petasis product from aminated Wang’s resins were optimized, but the final products were isolated in low yields
Brückner, Sébastien. "Mise en évidence d'une réaction tandem Stille/cycloaddition [4+2] : Application à la synthèse de nouveaux systèmes pentacycliques stéroi͏̈diens et étude mécanistique." Université Louis Pasteur (Strasbourg) (1971-2008), 2002. http://www.theses.fr/2002STR13123.
Full textIn order to synthesize thirteen membered macrocycles, we developed a strategy based on the differentiated reactivity of the two enoltriflate moieties of bis(enoltrifluoromethanesulfonates). This strategy involving palladium catalysed coupling reactions allowed the synthesis of polyunsaturated and stannylated derivatives. Instead of the expected macrocycles, the macrocyclization of these precursors leads, at room temperature, to several pentacyclic structures by a Stille/ [4+2] cycloaddition tandem reaction. This kind of structure is present in the xestobergsterol, a cytotoxic natural compound. Therefore we used this key step to synthesize other polysubstituted pentacyclic systems. Since this type of mild cyclization has no precedent in the literature, we investigated a mechanistic study. Due to several considerations and synthesises we postulated a palladium catalyzed mechanism which has to be proven
Radjagobalou, Robbie. "Etude expérimentale et modélisation d'une réaction de photooxygénation avec sensibilisateur soluble ou supporté dans des photoréacteurs continus milli-structurés éclairés par des LED." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0101.
Full textOrganic photochemistry becomes a key synthesis pathway for sustainable chemistry thanks to its ability to address molecular complexity and diversity with a “flick of a switch”, often in one step. Sensitized photooxygenations are particularly attractive: singlet oxygen 1O2 is here generated by photosensitization of the triplet molecular oxygen 3O2, most often in the visible range with catalytic amounts of an organic sensitizer (dye). Despite the several advantages, these reactions have not found widespread implementations in the chemical industry, mainly due to currently available technology based on outdated batch reactors (poor light penetration, high dilution) equipped with energy demanding mercury lamps (intensive cooling and optical filter needs). In that way, continuous flow microstructured technologies have recently emerged as alternatives to batch processing and their suitability for photoreactions has been highlighted; the combination with narrowly emitting LED light sources additionally enables energy savings, increased yields and selectivity. At present, however, there are few attempts to understand these benefits using a chemical engineering perspective. In keeping with this context, this thesis investigates photooxygenation in different continuous-flow microreactor devices with the aim at (i) understand how and why the operating conditions can affect the yield and the selectivity; and (ii) providemodelling tools for defining a methodology for smart scale-up. For that, three types of LED-driven microreactors were considered: the Vapourtec® photoreactor, the home-made spiral-shaped photoreactor and the advanced-flow G1 photoreactor from Corning®. As a case of study, the photooxygenation of -terpinene into ascaridole was selected, in the sustainable solvent ethanol and using rose Bengal as a sensitizer of industrial interest. In a first step, a revised protocol of actinometry using the Reinecke’s salt (visible domain) was proposed to measure the incident photon flux (i. e the one arriving at the reactor surface). It was successfully implemented in the spiral-shaped microreactor, and based on simplified 1D model, this parameter could be estimated. Secondly, the kinetic law based on all mechanistic steps was established for the chosen reaction. From this, the set of operating conditions potentially influencing the photoreaction rate were identified. Subsequently, experiments with soluble Rose Bengal were carried in both lab-scale and meso-scale microreactors, enabling to cover a large operating window and thus to collect an important database. Whatever the continuous-flow reactors, the conditions enabling minimization of sensitizer bleaching while achieving quantitative conversion were identified. A 1D model of representation, taking into account the Lambertian nature source and the potential reflection at the back optical surface, was proposed. It enabled to formalize the different coupled phenomena, to analyze and estimate the experimental trends at different scales. Finally, the photooxygenation of -terpinene was performed under continuous-flow with solid-supported sensitizer. The latter consisted in photoactive microgels (~300 nm) transported by the liquid phase: the sensitizer Bengal rose was grafted on a polymer matrix that had the ability to swell into water or alcoholic solvents and thus induced a decrease of their average refraction index. The underlying idea was to test a new-resource efficient photochemical synthesis concept that could circumvent the downstream separation processes and also protect the sensitizer from its ability to photodegrade during the irradiation time. The implementation of these photoactive microgels lead to very promising results, in terms of both conversion, bleaching reduction and reusability, and thus offer very interesting perspectives for supported photooxygenation in the future
Lopez, Sarah. "De nouveaux biocatalyseurs hétérogènes pour des réactions d'oxydation : des cristaux de métalloenzymes artificielles." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAV022/document.
Full textSince the industrial revolution, chemistry has continually thriven by developing new efficient processes at the expense of the environment. As an example, oxidation reactions are performed under harsh conditions with the use of toxic oxidants. With the emergence of green chemistry, catalytic processes using physiological metals and soft oxidants are privileged. Combining the advantages of biocatalysis and homogeneous catalysis, the design of novel bioinspired catalysts, consisting on the synthesis of artificial enzymes has recently emerged. These hybrids are composed of an inorganic complex, driving the reactivity of the enzyme, inserted into a protein, which drives the reaction selectivity. The thesis described new developments in original artificial metalloenzymes, based on the use of the NikA protein and Fe or Ru catalysts. First, a new hybrid has been developed by anchoring the Ru-bpza complex to NikA to catalyze alkene hydroxychloration with hypervalent iodine. Although excellent catalytic efficiencies were obtained, the stability improvement remains a major challenge for the industrial use of these catalytic processes, especially when oxidation chemistry is concerned. One possible strategy is based on the development of heterogeneous catalysis, by using a crystal/solution version of the artificial metalloenzymes thank to the cross-linked enzyme crystals (CLEC) technology. On the one hand, this technology allows to increase the stability and the recyclability of the catalysts. On the other hand, catalysis can be performed under a various reactions conditions (organic solvent, temperature, pH). Three reactivities have been developed with NikA/FeL-CLEC catalysts: (i) thioether sulfoxidation with NaOCl, (ii) alkene hydroxychloration with Oxone® and chloride source and (iii) oxidative cleavage of alkenes by O2 activation. To go further, new reactivities in cascade reactions have been explored combining either NikA-based CLEC developed, or different homogenous catalysts
Filippi, Alexandra. "Métathèse : nouveaux développements pour le flux continu et en chimie du phosphore." Caen, 2015. http://www.theses.fr/2015CAEN2006.
Full textThe first part of this thesis is dedicated to the study of new catalytic materials, so-called BioSILP for olefin metathesis. In these catalytic materials, an ionic liquid phase containing an ionically tagged metathesis catalyst (HG-II type) is immobilized on a bio-polymer support, alginate. The catalytic efficiency and the recycling ability of these supported catalytic materials (Bio-Ru-SILP) were evaluated for metathesis reactions to define the scope and limitations of this novel immobilization strategy. The second part of this work is dedicated to the development of a new synthetic route towards quaternary phosphonium salts, using as a key step for their synthesis, the olefin metathesis reaction of arylalkenylphosphonium salts. Various olefinic partners were studied. Excellent conversions could be obtained, however purification of the products is troublesome. Using Michael acceptors as olefinic partners afforded a new route to the synthesis of a wide variety of original phosphonium salts, by a unexplored catalytic reaction process: the tandem hydrophosphination/metathesis reaction
Lorton, Charlotte. "Développement de nouvelles méthodologies en organocatalyse asymétrique redox par les phosphines." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASF028.
Full textPhosphines play a crucial role as stoichiometric reagents in a variety of reactions, daily used in organic synthesis (e.g. Wittig, Mitsunobu, Staudinger and other transformations). Despite their usefulness, these venerable reactions suffer from several drawbacks, in particular, the concomitant formation of a stoichiometric quantity of phosphine oxide and the limitation to the formation of achiral or racemic compounds. In an effort to address these concerns, we have focused our attention on the development of catalytic tandem intramolecular “Michael addition/Wittig reaction” for the synthesis of cyclic compounds. Several substrates have been investigated such as dialkylacetylene dicarboxylate or allenoates, in the presence of carbonyl compounds. Moreover, the use of a chiral phosphine allowed us to access to enantioenriched N-containing heterocycles and cyclobutene derivatives via an asymmetric redox catalysis
Ben, Chaabane Tahar. "Transfert d'électron en micelles et vésicules : effet du potentiel électrique interfacial." Paris 11, 1987. http://www.theses.fr/1987PA112188.
Full textDamiron, Denis. "Développement de nouvelles stratégies Robustes, Efficaces et Orthogonales pour l’élaboration et la fonctionnalisation de matériaux polymères." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10324.
Full textThis thesis focuses on three different and innovative techniques studied as efficient and robust processes to elaborate functional polymers with controlled architecture or crosslinked materials and thin films. The first strategy exploits the orthogonal property of a famous click chemistry: the Copper (I)-catalyzed Azide–Alkyne Cycloaddition (CuAAC). We developed two complementary strategies based on the one-pot tandem combination of CuAAC and Controlled Radical Polymerisation techniques (CRP) to efficiently elaborate complex polymer architectures. The second strategy is focused on the thiol-ene chemistry as a click chemistry and its use for the functionalisation of polymers in order to obtain well defined architectures. A series of alkenefunctional polymers were synthesized by controlled polymerization techniques in order to investigate and compare the efficiency and orthogonality of both photochemically and thermally initiated thiol-ene click coupling reactions. Orthogonality of thiol-ene chemistry with CuAAC was also studied. The third strategy is inspired of new processes developed to perform crosslinked/functionalised materials by azide-ene couplings. We investigate a new strategy for the elaboration of crosslinked PDMS in bulk or in thin films with the use of a diazide as coupling agent. This last study combines analyses in rheology, chemistry and in thin layer
Roche, Maxime. "Couplages pallado-catalysés de N-tosylhydrazones : synthèse d’oléfines apparentées à l’isocombrétastatine A4." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA114843.
Full textThis thesis work concerns the development of new palladium catalyzed cross-coupling reactions of N-tosylhydrazones and their applications to the synthesis of isocombretastatin A4 (isoCA-4) analogs. The first part of this work is dedicated to the study of the reactivity of hindered N-tosylhydrazones in coupling with aryl halides. A protocol has been developed to synthesize ortho/ortho’-disubstituted 1,1-diarylethylenes related to isoCA-4. Another part of this thesis is dedicated to the development of tandem reactions involving N-tosylhydrazones. Two new reactions are reported, a Barluenga cross coupling-Buchwald-Hartwig cross coupling tandem reaction as well as a Barluenga cross coupling-Suzuki-Miyaura cross coupling tandem reaction. In the last chapter, oxidative coupling of indoles with N-tosylhydrazones was examined. N-vinylindoles synthesized by this way showed promising antiproliferative activities
Giorgi, Pascal. "Nouvelles réactions à économie d'atomes et d'étapes basées sur la catalyse par des nanoparticules d'or et la multicatalyse. Applications dans la synthèse de chimie fine et des odorants." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4127.
Full textElaboration of synthetic methods based on metal-catalyzed reactions has been a hot topic in organic chemistry. Despite good efficiency, catalysis proceeding homogeneously, are limited in the operation of recovering/recycling of the catalysts. An important stress was placed to design catalysis, offering both the efficiency of homogeneous catalysts and the recyclability of heterogeneous catalysts. In this context, metal nanoparticles merged as a key tool, due to their unique physical and chemical properties. Notably, Au NPs have shown remarkable catalytic activity in the oxidation of activated alcohols under O2 atmosphere. Since now, the access to more complex molecules is the next step forward for this field, we envisioned multicatalytic roads, based on the oxidation of activated alcohols via supported Au NPs. Our choice of using solid catalysts was relevant, since nanostructured catalysts for which the fraction of active sites are located on the surface, limit the risk of cross-quenching. The latter carbonyl formed, could be further converted in situ, via tandem protocol. Herein, we developed novel, atom- and step-economical bicatalytic one-pot processes, to access substituted chromenes/quinolines (53-93%) by tandem oxidation/hetero-Michael addition/aldolisation combining nanocatalysis and base catalysis, ortho-THCs (50-81%) via tandem oxidation/arylation/cyclisation combining nanocatalysis and supported catalysts and a tandem cascade oxidation/hydrolysis to access HMLA (86%, sel 93%). A large panel of products of biological activity relevance, pertaining to the fragrance chemistry or aiming in some cases, pre-industrial scalability via continuous flow applications
Monnier-Benoit, Nicolas. "Étude du processus tandem réaction de Michael-Azacyclisation des imines, énaminomes ou énaminoesters chiraux : application à l'utilisation d'oléfines électrophiles substituées pour la synthèse de synthons azotés chiraux." Le Havre, 2003. http://www.theses.fr/2003LEHA0001.
Full textAllous, Iyad. "Synthèse de composés diaza-spiraniques analogues d'alcaloïdes cytotoxiques et anticancéreux." Le Havre, 2010. http://www.theses.fr/2010LEHA0004.
Full textOur 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
Gagnon, David. "Méthodologie impliquant une réaction de Mitsunobu et un réarrangement signatropique [3,3] en tandem afin de préparer des hétérocycles énantio-enrichis. Application à la synthèse totale de la (+)-aspidofractinine." Thèse, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/5101.
Full textAlsalim, Rana. "Contribution à la synthèse totale de la céphalotaxine." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA114811/document.
Full textFor more than 40 years the chemists were interested in the extraction, in the biological activity and in the synthesis of the homoharringtonine, a natural ester of cephalotaxine, which is a powerful antileukemic compound of therapeutic use, in particular against the leukaemia resistant to tyrosine kinase inhibitors. These alkaloids are extracted from Cephalotaxus, conifers native of the South of China with extremely slow growth. The objective of this work thus consisted in developing a concise synthesis of the cephalotaxine, to limit the recourse to the endangered vegetable resource The developed strategy requires an intermolecular Heck-coupling of electronically and sterically deactivated demanding substrates. The preliminary results having been disappointing, the first objective consisted in developing the use of the model of the experimental design in total synthesis because the classic methodology of variation of a single parameter at the same time said of "one by one" was ineffective. The application of a complete factorial design overcomes this problem by a model study, allowing to determine the optimized parameters to make this coupling reaction effective. We then synthesized the precursors from naturally abundant safrol and 2,3-butanedione then realized the Heck coupling with the aim of the access to the precursor AC containing all the atoms of carbon of cephalotaxine and the features required for its later cyclization in pyrrolobenzazepine ABC fragment. The o-iodized homopiperonylic alcohol led in certain conditions to an isochromane through a tandem Heck-oxa-Michael reaction. Finally, we have functionalized the Heck and hydro-arylation products obtained with 69-70 % yield in position C3 by different methods allowing us to validate our strategy to access these alkaloids
Nguyen, Khac Minh Huy. "Activation de liaisons C-H au moyen d’un système catalytique bio-inspiré pour la synthèse d’hétérocycles d’intérêt pharmacologique." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB023.
Full textNaturally occurring metalloenzymes constitute a rich source of inspiration for the design of synthetic catalysts because of their ability to perform controlled aerobic oxidations under very mild conditions. Among metalloenzymes, copper amine oxidases (CuAOs) promote selective aerobic oxidation of primary amines through the cooperation of a quinone-based cofactor (topaquinone) and a copper ion. Recently, there has been a boost in the development of biomimetic catalysts for the aerobic oxidation of amines to imines owing to the importance of imines as pivotal intermediates in the synthesis of fine chemicals and pharmaceuticals. In our laboratory, a CuAOs-like homogeneous co-catalytic system has been described for the atom-economical oxidation of primary amines to imines, under ambient air. The catalytic process combines two redox couples in a way reminiscent of CuAOs: the o-iminoquinone organocatalyst 1ox, generated in situ from the corresponding o-aminophenol 1red, is the substrate-selective catalyst, whereas the copper (II) salt serves as an electron transfer mediator. Interestingly, low loadings of biocompatible CuII and organocatalyst 1ox are sufficient to activate the α-C-H bond of primary aliphatic amines, which are converted, under ambient air, into cross-coupled imines through a transamination process that leads to the homocoupled imine intermediate, followed by dynamic transimination. The mild reaction conditions are highly favorable from a synthetic viewpoint, in particular for trapping the unstable alkylimines in situ for further reactions. So, we have envisioned the use of this bioinspired co-catalytic system in the one-pot synthesis of heterocycles of pharmacological interest. In the first part of the thesis, we envisioned that the Cu(II)/1ox cooperative system might be utilized to synthesize novel 1,4-benzoxazine derivatives. In the specific case of R1R2CHCH2NH2 amines, the catalytic process should stop after a few turnovers, because the catalyst 1ox should be trapped through inverse-electron-demand Diels-Alder (IEDDA) reaction with the simultaneously in situ generated tautomeric enamine form of the alkylimine extruded during the catalytic process, leading to 1,4-benzoxazine derivatives. Unfortunately, this protocol failed to produce the expected cycloadducts in acceptable yields as enamines rapidly decomposed under ambient air. For this reason, we have developed a tandem oxidation-inverse electron demand Diels-Alder reaction as an alternative: a stoichiometric amount of activated MnO2, in deaerated methanol, was then sufficient to convert various o-aminophenol derivatives into o-iminoquinone heterodienes which were trapped in situ by different enamine dienophiles leading to the expected 1,4-benzoxazine derivatives under mild conditions. The possibility of introducing variations in both cycloaddition partners led to highly substituted 1,4-benzoxazine cycloadducts with up to five elements of diversity. Among these compounds, a 3,3-diphenyl-substituted-1,4-benzoxazine derivative was identified as an effective neuroprotective agent in newborn mice, suggesting that it could be a potential candidate for the treatment and prevention of cerebral palsy. In the second part of the thesis, the Cu(II)/1ox cooperative system has been successfully used for the catalytic oxidative coupling of a diverse range of activated and non-activated primary amines with o-amino-anilines under ambient air leading to benzimidazoles of biological interest through multistep oxidation and nucleophilic addition reactions. Through the variation of both solvent and coupling partners, MeOH proved to be the best solvent for this transformation because it provided the ideal balance of 1ox solvation and reaction rate, except when reactive N-alkyl o-aminoanilines were used as in situ imine traps, due to the concomitant formation of a benzimidazole byproduct originated from MeOH itself. (...)
Royer, Frédérique. "Vers la synthèse totale de la paulitine." Phd thesis, Ecole Polytechnique X, 2004. http://pastel.archives-ouvertes.fr/pastel-00000949.
Full textFunel, Jacques-Alexis. "Approches de synthèse du trycicle ABC du FR182877." Palaiseau, Ecole polytechnique, 2004. http://www.theses.fr/2004EPXX0038.
Full textErmolenko, Lioudmila. "Photooxydation des alcanes catalysée par les polyoxotungstates en présence d'oxygène moléculaire." Cachan, Ecole normale supérieure, 1997. http://www.theses.fr/1997DENS0010.
Full textFourgeaud, Pierre. "Synthèse et réactivité de nouvelles familles d'hétérocycles phosphorés." Montpellier 2, 2007. http://www.theses.fr/2007MON20250.
Full textPhosphorus molecules, due to their key roles in biochemistry and wide chemical diversity, are intensively studied because of their potential biological activities. Those research led to the commercial use of phosphorus molecules in the field of medicine and agrochemistry. We synthesized five and six membered rings using ring closing metathesis and to avoid some drawbacks of such a method, we used allenic compounds with nucleophilic or electrophilic compounds. We managed to synthesize new heterocycles and we set up a new chain of reactions. Finally, we introduced molecular diversity on the previously synthesized heterocyles using pallado-catalysed arylation, hydroxyl- and aminoalkylation reactions using parallel synthesis. Five families of heterocycles were obtained and more than eigthty compounds were submitted to biological evaluatin in the agrochemistry field
Saghbini, Samar. "Étude photophysique de la cinétique de formation de complexes." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL032N.
Full textHong, Xiang. "Nouveaux catalyseurs hétérogènes chiraux pour le dédoublement cinétique hydrolytique des époxydesTERMINAUX." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00770302.
Full textMariaule, Gaëlle. "Accès original aux hétérocycles par la catalyse organométallique : développement de nouveaux inhibiteurs de kinases." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05P612/document.
Full textMy thesis proJect is organized around two main topics having in common organometallic chemistry and the synthesis of heterocycles.Firstly, we were interested in a methodology for the synthesis of tetrahydrocyclopenta[c]acridines. These compounds are synthesized in three steps from various quinolines. The key step is a cobalt-Catalyzed intramolecular Pauson-Khand reaction. Some compounds of this family exhibit selective Cyclin Dependent Kinases (CDKs) inhibition, particulary against CDK2, in the submicromolar range. A hit compound has been identified, and then using data from co-Crystallization with CDK2 and molecular modeling, followed by the study of structure-Activity relationships, the rational design of a second generation of molecules has been investigated. The most advanced compound has an IC50 of 300 nM against CDK2/cyclin A with an excellent metabolic profile. In the second axis of research, we have studied and developed a new silver-Catalyzed tandem addition/cyclization reaction with carbon nucleophiles. The systems studied are (hetero)aromatics compounds having an aldehyde group and in ortho-Position an alkynyl group. The synthetic strategy leads to 1H-Isochromene derivatives by creating two new bonds. A thorough study of the tandem reaction allowed us to obtain a wide range of isochromene derivatives, highlighting the influence of different substituents carried by the alkyne group or on the (hetero)aromatic substrates; and also to investigate the use of different carbon nucleophiles (alkynes, aromatics and heteroaromatics). The limitations of the tandem reaction have also been identified
Funel, Jacques-Alexis. "Approches de synthèse du tricycle ABC du FR182877." Phd thesis, Ecole Polytechnique X, 2004. http://pastel.archives-ouvertes.fr/pastel-00002300.
Full textGuillam, Anne. "Synthèse et cycloadditions [4+2] des 1,4-dialkoxybutadiènes." Rouen, 1997. http://www.theses.fr/1997ROUES078.
Full textHémelaere, Rémy. "Mise au point de réactions tandems catalytiques incluant une étape d'isomérisation pour la synthèse de molécules naturelles." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S173/document.
Full textSome of the new challenges of modern synthetic chemistry are: atom economy, employment of catalytic processes, avoidance of toxic reactants and limitation of purification steps. A lot of work has been devoted to the development of tandem reactions. A new reactivity could be generated in a molecule thanks to an isomerisation (or migration) reaction of an alkene. This reaction often needs an hydride specie which comes from a transition metal catalyst. This PhD thesis is about the development of new tandem reactions in which at least one step is an isomerisation of an olefin. A great attention has been dedicated to the synthesis of vinylboronates especially with a cross-metathesis strategy. These intermediates are of great importance in organic chemistry and can be useful in a wide range of reactions. One of those reactions is the transformation of vinylboronates to allylboronates thanks to an isomerisation step. Allylboronates can then react with aldehydes to generate homoallylic alcohols with total diastereoselectivity. These new reactions have found applications in total synthesis of natural molecules with a 2,3-dihydrobenzofuran core
Rajaona, Tovoarinjara. "Raffinement local de maillage avec une méthode de décomposition de domaine : application au calcul de la dispersion des polluants dans le voisinage d'une source." Rouen, 2000. http://www.theses.fr/2000ROUES038.
Full textPerny, Sébastien. "Alignement de cristaux liquides par irradiation en lumière linéairement polarisée de film minces de polymères photoréticulables." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0042.
Full textCazin, Bernadette. "Contribution à l'étude de générateurs chimiques d'oxygène singulet en solution aqueuse." Paris 6, 1986. http://www.theses.fr/1986PA060049.
Full textSayes, Morgane. "Développement d'une réaction d'amidation utilisant le diphénylsilane en tant qu'agent de couplage et d'une réaction de borocyclopropanation photochimique." Thèse, 2019. http://hdl.handle.net/1866/23405.
Full textThis manuscript describes the work carried out in Pr. Charette’s laboratory between 2015 and 2019. It can be divided into two different topics: the development of new amidation strategies and the development of new cyclopropanation methodologies. Amide synthesis is still a challenge for the scientific community nowadays. Indeed, the development of simple, robust, atom economical and environmental friendly procedures remain one of the research priority in organic chemistry. To contribute to this field, an amide synthesis methodology has been developed by using diphenylsilane as a coupling reagent. The latter is commercially available, stable and cheap. Moreover, only a siloxane and dihydrogen are generated during the reaction. The developed methodology has also been applied to the synthesis of a series of di- and tripeptides. The cyclopropane moiety has been increasingly used in pharmaceuticals. Indeed, this moiety can influence different crucial parameters in the development of bioactive molecules. The development of new cyclopropanation methodologies is therefore a relevant field. Borocyclopropane synthesis is of particular interest: as a matter of fact, these compounds can create structural diversity via boronate functionalization. In order to obtain a user-friendly, robust and greener chemical process, a photochemical approach using continuous flow technology has been favored. A photoredox borocyclopropanation of styrenes has been developed; the latter is carried out under UV-A irradiation with xanthone as a photosensitizer. Mechanistic studies have supported that this transformation proceeds according to two concurrent photoredox catalytic cycles. Finally, a new diiodo reagent bearing a pinacol boronate group and a trimethylsilyl group has been developed to access gem-disubstituted cyclopropanes. The bases of a UV-visible photochemical process using this new reagent have then been established. Thereby, the first example of a gem-borocyclopropyl silane derived from styrene has been synthesized.
Davi, Michaël. "Développement d'une nouvelle méthodologie d'oléfination catalysée par les complexes de cuivre : applications dans des réactions en tandem." Thèse, 2008. http://hdl.handle.net/1866/6553.
Full text