Dissertations / Theses on the topic 'Carbène N-hétérocyclique de cuivre(I)'
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Akhdar, Ayman. "Synthesis, Modification And Click Of Arylopeptoids Using Carbene-Based Catalysts." Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2022. http://www.theses.fr/2022UCFAC117.
Full textArylopeptoids (i.e. oligomeric N-substituted aminomethyl benzamides) is a class of peptoid-inspired oligoamides with aromatic backbone. They retain advantageous features of peptoids such as straightforward synthesis by submonomer approach and conformational preferences governed by cis-trans isomerism of N,N-disubstituted amides. These N-alkylated aromatic oligoamides may be developed as proteomimetics or scaffolds for multivalent display. The aim of this thesis was to explore the chemical diversity accessible from linear and cyclic arylopeptoids through Click chemistry using Copper carbene as catalyst. First, access and properties of Copper (I)-N-heterocyclic carbene catalyst was exposed. Also, an extension of the quantitative NMR was presented to study the purity of this catalyst and other organometallic compounds. The development of an efficient CuAAC protocol on-resin using Copper (I)-N-heterocyclic carbene catalyst for the functionalization of arylopeptoids has allowed the efficient preparation of a library of linear oligomers carrying several triazole-type side chains. Beside, combinatorial and sequential approaches have been implemented leading to huge accessible chemical diversity. Post-modification of the triazoles into triazoliums has led to several series of triazolium-based arylopeptoids exhibiting amphipathic character. Their antibacterial activity against a panel of bacterial strains has been evaluated. The access to 3-dimensional crown- and tube-like structures from constrained arylopeptoid macrocycles by CuAAC reaction using the Cu-NHC catalyst also proved to be efficient with a selectivity depending on the spatial preorganization of the cyclic core and proper choice of the NHC catalyst. Finally, the access to H-shaped arylopeptoids was studied using CuAAC reaction on resin. Overall, this work highlights the potential of the Copper (I)-N-heterocyclic carbene as catalyst for CuAAC to perform on-resin poly-functionalization of arylopeptoids and to build complex 3D-architectures
Broggi, Julie. "Contribution des catalyseurs contenant un carbène N-hétérocyclique pour la chimie des nucléosides." Phd thesis, Université d'Orléans, 2009. http://tel.archives-ouvertes.fr/tel-00452644.
Full textLefebvre, Jean-François. "Synthèse et propriétés de ligands de type carbène N-hétérocyclique conjugués à une porphyrines." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20141/document.
Full textIn addition to the usual inner coordination site of porphyrins, it is possible to functionalize the macrocycle by external coordination sites. This PhD thesis is devoted to the functionalization of two neighboring b-pyrrolic carbons in order to obtain porphyrins fused to peripheral N-heterocyclic carbene ligands (NHC).NHC ligands are known to display outstanding electronic properties which render them important ligands in the fields of catalysis and organometallic chemistry. The aim of this PhD work was to study the influence of the porphyrin on the electronic properties of the peripheral NHC ligand, and to modulate the electronic and catalytic properties of anchored metal complexes according to the chemical modifications brought to the porphyrin, ie. its metallation or the protonation of the free-base porphyrin.Firstly, the different synthetic procedures to obtain porphyrins fused to imidazolium rings were developed. These imidazolium salts are the key precursors of the porphyrin-NHC ligands. In order to study the catalytic properties of metal complexes containing porphyrin-NHC ligands, several palladium(II) complexes were synthesized and characterized. The study of the catalystic properties of these complexes showed that better catalytic activities were observed if the porphyrins contain a metal cation. Then, the electronic properties of these NHC ligands were evaluated for (NHC)Rh(COD)X and (NHC)Rh(CO)2X complexes with X = I or Cl
Passays, Johan. "Nouveaux ligands mixtes de type phosphore / carbène N-hétérocyclique : synthèse et applications en catalyse asymétrique." Thesis, Rouen, INSA, 2011. http://www.theses.fr/2011ISAM0008.
Full textA straightforward method for the preparation of new bidentate ligands containing aphosphine or a phosphite and a carbene function was developed. Different phosphorus-imidazolium compounds were prepared according to this method. First, diphenylphosphine-NHC ligands featuring a stereogenic center a to the phosphine were synthesized from b-hydroxyesters. This strategy was then extended to the preparation of phosphite-imidazoliumand dialkylphosphine-imidazolium compounds. Complexation of these phosphorus-NHCligands with different metals like Ir or Rh was performed in order to study there catalytic properties in asymmetric hydrogenation
Benhamou, Laure. "Ligands carbènes N-hétérocycliques : de la complexation sur le ruthenium(0) aux carbènes anioniques." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/1189/.
Full textThis work concerns the use of N-heterocyclic carbenes as ancillary ligands or as active species in catalysis. The first part deals with the chemistry of N-heterocyclic carbenes and their imidazolium precursors with the ruthenium(0) complex Ru(CO)2(PPh3)3 (Roper’s complex). We have shown that these reactions need to be chelation-assisted and the nature of directing group is determinant. It results that the C-H activation in position 2 of the imidazolium salt by the Ru(0) complex occurs only with a precoordinated homoallylic arm on one nitrogen and gives a Ru(II)-alkyl complex with a five-membered metallacycle. A Ru(0)-NHC complex has also been prepared by reaction of the NHC-olefin ligand and the Roper’s complex. The reactivity of this Ru(0)-NHC-olefin complex with acids allowed the observation of intermediates involved in the isomerisation process of the olefinic arm which ultimately led to the five membered metallacycle. The second part of this work focuses on the study of a new five-membered anionic NHC, the imidazol-2-ylidene-4-olate. First, we have developed an easy synthetic method to prepare the imidazolium precursor of this carbene and we have studied its reactivity with electrophiles. Then, we have studied the coordination chemistry of the anionic carbene. In particular we have found a way to functionalize the enolate moiety after complexation on a metal center. According to this method we have synthesized several M-NHC complexes (M = Rh, Cu) with different functional groups on the backbone of the heterocycle. These modifications were found to have a deep influence on the electronic properties of the ligand
Phung, Quang Linh. "Synthèse de ligands chiraux de type phosphine-phosphite et phosphine-carbène N-hétérocyclique pour la catalyse asymétrique." Rouen, 2005. http://www.theses.fr/2005ROUES033.
Full textCatalytic asymmetric synthesis using organometallic reagents has become one of the most active areas of research in modern organic synthesis. To achieve the highest levels of reactivity and selectivity in catalytic enantioselective reactions, several reactions parameters must be optimized. Among them, the selection and design of the chiral ligand is perhaps the most crucial step. We have developed two families of bidentate ligands : phosphine-phosphite and phosphine N-heterocyclic carbene. These two series of ligands have a chiral center to the α-position next to the phosphine moiety. This stereogenic α-position could be of great importance since the phosphorus atom is directly associated with the transition metal in the asymmetric reaction. Phosphine-phosphite ligands were tested in the Rh-catayzed asymmetric hydrogenation (ee up to 84%) and hydroformylation (no asymmetric induction). Phosphine N-heterocyclic carbene ligands were tested in the Ir-catalyzed asymmetric hydrogenation and hydrosilylation (no asymmetric induction), and with promising results in the Suzuki-Miyaura cross-coupling reaction
Brousses, Rémy. "Études structurales de carbènes de Fischer et de complexes carbéniques N-hétérocycliques par diffraction des rayons X à haute résolution." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2256/.
Full textHigh resolution X-ray diffraction analyses enable the experimental determination of the charge density distribution within compounds. In this context, we have investigated the structure of Fischer carbenes and N-heterocyclic carbene (NHCs) complexes of the first-row transition metals series, Mn(I) and Fe(II). At first, on the basis of the high-resolution structural analysis of the MeCp(CO)2Mn=C(Me)OEt complex, we will show that non-covalent interactions between the ethoxy substituent of the carbene ligand and the carbonyl ligands are responsible of the conformation of the Mn(I) piano-stool alkylalkoxy carbene complexes. Analysis of the Cp(CO)2Mn=C(Ph)OC6H2Cl3-2,4,6 complex revealed the existence of a non-covalent interaction between the aryl substituent and the proximal carbonyl group. We will show that, beyond its incidence on the conformation of the complexes, this type of interaction also induces a red-shift of the IR ?CO frequencies of the carbonyl ligand and as a consequence, modifies their response relative the electron-donicity of the ancillary ligands. Then, we were prompted to extend these studies to Mn(I) and Fe(II) NHC piano-stool complexes of the type Cp(CO)2Mn(NHC) and Cp(CO)2Fe(NHC). We will show that a non-covalent interaction between the aryl substituent of the NHC ligand and the proximal carbonyl group also occurs in this type of complexes. In the last part, we will focus on the synthesis and the structural characterization of Mn(II) NHC complexes resulting from the one-electron oxidation of the Cp(CO)2Mn(NHC) complexes cited above. These radical complexes appeared to be stable and one of them could be analyzed by high-resolution X-ray diffraction
Guernon, Hannah. "Développement d'une nouvelle famille de ligands carbène N-hétérocycliques anioniques basés sur les Ylures de N-iminoimidazolium." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6585.
Full textLing, Xiang. "N-heterocyclic carbenes coated nanocrystals and supracrystals." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066334/document.
Full textNanomaterials have received extraordinary attention owing to their unique properties, strongly associated to their nanoscale dimensions. In particular, noble metal (Au, Ag) nanoparticles (NPs) exhibit particular mechanical, electronic, optical and magnetic properties and present a high potential for developing applications in many domains with important societal impacts. Due to their higher stability by comparison with other metal-based nanoparticles, Au NPs have been extensively investigated for research in nanotechnology. In the last decades, N-Heterocyclic carbenes (NHCs) have emerged as an essential class of neutral ligands in organometallic chemistry. NHCs are characterized by their high synthetic flexibility, their specific geometry, and a very strong metalCcarbene bond in metal complexes. All these properties have been widely studied and exploited for applications in homogeneous catalysis and for the development of biologically active complexes. By comparison, the use of NHCs in nanomaterials remains largely unexplored. In this work, the potential of NHC ligands in the field of nanomaterials, as coating agents for gold nanocrystals synthesis, stabilization and self-assembly into supracrystals has been explored. First, well-defined silver and gold–NHC complexes with different well-known NHC ligands are investigated for their relevance to generate stable nanocrystals (NCs) under reductive conditions with a good control of nanocrystals size. We demonstrate that both Au and Ag NCs can be formed by reduction of metal-NHC complexes with amine-boranes. The efficiency of the process and the average size and size distribution of the nanocrystals markedly depends on the structure of the NHC ligand. However, we demonstrate in this part that different pathways are involved to generate nanocrystals from Au or Ag precursors, as a specific reaction is observed between Ag-NHCs and thiols leading to the formation of silver thiolates whereas the corresponding Au-NHCs remain unchanged
Kuhl, Sébastien. "Activation de liaisons carbone-halogène et carbone-azote par des catalyseurs de nickel(0) ligandés par un carbène N-hétérocyclique." Nancy 1, 2005. http://www.theses.fr/2005NAN10112.
Full textThis work describes the preparation of new nickel catalysts liganded with N-heterocyclic carbenes for the reduction of (poly)halogenated arenes and imines and for the N,N'-diarylation of aromatic diamines. In a first part, the Ni(0)/IMes (1/2) catalyst, associated to i-PrONa, was used for the reduction of (poly)chlorinated arenes. Carbon-fluorine bonds of fluoroarenes can also be activated by the Ni(0)/IMes (1/1) catalyst and be reduced in the presence of the secondary alkoxide Et2CHONa. Transfer hydrogenation of imines into amines is also possible with this catalyst. In the second part, the development of a new nickel catalyst, noted Ni(0)/IPr (1/2), for the N,N'-diarylation of aromatic diamines is described. The synthesis of new N,N'-diaryldiamines containing a 4-[10-(4-aminophényl)-9-anthryl]aniline moiety is reported. It has been shown that the diaryldiamines possess fluorescent properties and that they were reversibly oxidized into stable di(radical cation)s
Ménard, Alain. "Étude de la formation d’indoles via un intermédiaire diaziridine et synthèse d’une nouvelle famille de ligands carbène N-hétérocycliques anioniques à partir d’Ylures de N-sulfonyliminoimidazolium." Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5412.
Full textWolf, Joffrey. "Préparation de précurseurs de carbènes N-hétérocycliques bidentes, étude de leur complexation et catalyse." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00168421.
Full textstabilité et très actif en comparaison à d'autres ligands.
Les récents travaux sur la synthèse de ligands bidentes comportant un NHC et un groupement azoté coordonnant, puis de complexes de palladium, rhodium et iridium très actifs en catalyse, nous ont orientés vers la préparation de ligands analogues avec des hétéroatomes différents.
Dans cette thématique nouvellement développée au sein de notre équipe, nous avons mis au point deux méthodes de synthèse originales donnant accès à de nouveaux précurseurs de carbènes N-hétérocycliques, composés d'un groupement imidazolium et d'un second groupement
coordonnant qui sera soit une phosphine, soit un thioéther.
L'étude de ces ligands a permis de développer une chimie de coordination riche avec Ni, Pd, Rh, Ru et Ir. Ainsi, quatre modes de coordination ont été mis en évidence : soit une monocoordination de l'hétéroatome ou du NHC, soit une double coordination de l'hétéroatome et du carbène Nhétérocylique selon des modes dit « normal » ou « anormal ». Nos études ont montré que le mode de coordination adopté par les ligands dépendait des conditions expérimentales, de la réactivité du métal et de son affinité pour l'hétéroatome.
L'obtention de tels complexes a permis d'effectuer quelques tests préliminaires en hydrosilylation et hydrogénation avec le rhodium(I). Une étude approfondie de la réaction de couplage d'un organomagnésien et d'un halogénure d'aryle (réaction de Kumada-Corriu-Tamao) a été menée avec les complexes du nickel(II).
Magrez-Chiquet, Magaly. "Alkylations asymétriques catalysées au cuivre mettant en jeu des systèmes polyéniques conjugués." Rennes, Ecole nationale supérieure de chimie, 2013. http://www.theses.fr/2013ENCR0015.
Full textNew methodologies in Copper-catalyzed asymmetric C-C bond formations were developed. A highly regio- and enantioselective 1,6-Conjugate Addition of dialkylzincs to linear dienones was developed using a Cu/DiPPAM catalytic system. The 1,6 adducts were then valorized through a 1,6/1,4- sequential conjugate addition process. Non-Linear Effects associated with DiPPAM ligand were studied on cyclic and acyclic di(enones). N-heterocyclic carbenes and Copper led to good enantio- and regioselectivities in Asymmetric Allylic Alkylation of Grignard reagents and dialkylzincs to allylic phosphates and alkenyl allylic phosphates
Cassirame, Bénédicte. "Couplages C-C utilisant des triarylbismuthines catalysés par le PEPPSI." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1116.
Full textMetallocatalysed crosscoupling reactions have been highlighted by the attribution of the 2010 Nobel Chemistry Price since they allow CC bond formation when classical SN1 or SN2 do not permit it. Furthermore, they give access to many pharmaceutics and agronomic compounds but also molecules used for their supramolecular properties. Nowadays, reactions are really efficient but reactants are not always readily accessible and can't be classified as green reagents. Since all its atoms act over the catalytic process and because they are not considered as toxic so far, triarylbismuthines may be a good alternative to circumvent the limitation described above. However, they suffer a main drawback, their reductive dimerisation. In order to avoid this side-reaction, a new greenest process has been developed on a benchmark reaction based on PEPPSI, an NHC/Pd catalyst. These conditions gave usually excellent yields, either for the biaryle or heterobiaryle crosscoupling reaction. The range of substituents is really wide on the aryle halide moiety but slightly more limited on the triarylbismuthine reagents. Then, this catalytic process has been applied without modification to an elimination/crosscoupling domino reaction. A GC/MS and 13C NMR supported comparative kinetic study showed that a 2nd order elimination take place before the C-C bond formation. Fluoride anion and triarylbismuthine act together. Therefore triarylbismuthine play a dual role: base and aryl transfer reagent. This mechanism study led to chimioselective reactions that allow many paths for the synthesis of Ar-Ar-C C-Ar containing compounds with a good control on geometry of this highly conjugated structure. This catalytic process allows also bromocoumarine C-Br bond activation. Thus, crosscoupling may be selectively performed at the 3-, 4- or 6- position of coumarines. The reactivity order difference of these positions even allow hightly selective mono crosscoupling reaction on 3,4- or 3,6-dibromocoumarines for further biological application. To conclude, our PEPPSI based greenest process avoid the dimerisation of bismuthines and give easy access to many compounds of great interest either for their biological or physical properties
Gojon, Sophie. "Carbènes N-hétérocycliques : nouvelle méthode de synthèse et activité catalytique pour la réticulation de silicone." Toulouse 3, 2011. http://www.theses.fr/2011TOU30321.
Full textThe main objective of this thesis is to study the synthesis of N-heterocyclic (NHCs) and their catalytic activity toward silicone elastomer formation
Hippolyte, Laura. "New syntheses of N-heterocyclic carbene-stabilized gold nanoparticles." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS148.pdf.
Full textOver the past decade, N-heterocyclic carbenes (NHC) have drawn considerable interest in the field of materials chemistry. Indeed, this relatively new class of ligands forms strong bonds with a wide range of metals and their structures and electronic properties can be tuned “at-will” through organic synthesis. This strong bond is of particular interest for gold nanoparticles. Indeed, gold nanoparticles have many potential applications, for example in sensors, catalysis or medicine, but those potential applications are sometimes hindered by a lack of stability of the surface ligand. A few syntheses of NHC-stabilized gold nanoparticles have already been described in the literature but each presents their own set of drawbacks. This thesis work has focused on the development of new syntheses of NHC-stabilized gold nanoparticles. First, by revisiting a literature procedure starting from imidazolium salts, we managed to develop a one-pot synthesis starting only from commercially available AuCl, NaBH4 and easily synthesized imidazolium salts. A totally new synthesis was developed using NHC-boranes, which are stable Lewis adducts. Here, we reported for the first time their use as a 2-in-1 reagent, able to reduce the metallic precursor and provide the nanoparticles stabilizing ligands. Finally, we are the first to report a synthesis of gold nanoparticles stabilized by mesoionic carbenes (MIC). MICs are a sub-class of NHCs synthesized by well-known “click-chemistry”, which present unique electronic properties. Throughout this work, special care was taken to characterize the nanoparticles, notably by XPS
Forcher, Gwénaël. "Vers la synthèse de carbènes N-hétérocycliques chiraux." Phd thesis, Université du Maine, 2013. http://tel.archives-ouvertes.fr/tel-01019677.
Full textJean-Baptiste, dit Dominique François. "Synthèse et caractérisations physico-chimiques de complexes métalliques comportant des ligands multidentes bis(carbène N-hétérocyclique) fonctionalisés : évaluation catalytique en couplage de Suzuki-Miyaura." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/347/.
Full textSince the pioneer work on metal N-heterocyclic carbenes (NHCs) and the isolation of free thermally stable NHCs, intensive activity research has been focused on the organometallic chemistry of this class of ligands. In this context, we decided to design a new class of amide or alcohol-N-functionalised bis(NHC) ligands. Diimidazolium salt precursors linked together by flexible or rigid, were obtained following short and modular synthetic pathways. Gold(I), Gold(III), Palladium(II) and Nickel(II) complexes were prepared following the carbene-transfer route of silver(I) precursors or by direct metallation of azolium salts in the presence of a mild base. Gold(I) and Ni(II) complexes have been characterized by single crystal X-ray diffraction analyses and the electrochemical and luminescence properties of the Au(I) and Au(III) compounds have been studied. Finally, the catalytic activities of Ni(II) and Pd(II) NHC complexes were evaluated in the Suzuki-Miyaura cross-coupling
Almallah, Hamzé. "Systèmes confinants pour la catalyse homogène." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF011.
Full textDescribed herein are the stepwise syntheses and properties of three types of complexes based on sterically encumbered N-heterocyclic carbenes (NHCs): 1) Pd-PEPPSI complexes with an unsymmetrical imidalolylidene ligand having its N atoms substituted by a bulky 9-alkyl-9-fluorenyl (AF) group and an aryl group. These turned out to be very active Suzuki-Miyaura cross coupling catalysts with an activity comparable to previously reported, highly performing "symmetrical" analogues which bear two identical AF substituents. These findings illustrate the high stabilising effect of each individual AF group; 2) Trigonal copper(I) complexes with the general formula [Cu(Im)(2,2'-dipyridylamine)]BF4 in which the NHC ligands are symmetrical or not. Here again the AF substituents ensure complex stability with respect to air when compared to analogues displaying sterically non-bulky substituents. One of the complexes, namely [Cu((EtF,Ph)-Im)(2,2'-dipyridylamine)]BF4, was found to be strongly luminescent in solution and in the solid state; 3) Pd-PEPPSI complexes in which calix[4]arene-substituted phenyl moieties have been grafted on both N atoms, these behaving as potential receptor units. Owing to the presence of the calixarene termini, complexes of this type were found to self-assemble, thereby resulting in dimers with sterically highly protected metal centres. The formation of such species was correlated to the catalytic performance of these complexes
Haumesser, Julien. "Synthèse et caractérisation d'assemblages multi-porphyriniques à espaceurs NHC." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01017421.
Full textOertel, Anna Magdalena. "Synthèse et réactivité de complexes du nickel(II) comportant des ligands carbène N-hétérocyclique : des réactions de couplage C-C croisé à l'activation de liaisons C-H." Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/OERTEL_Anna_Magdalena_2010.pdf.
Full textThe research in this thesis targets some aspects of the chemistry of nickel-N-heterocyclic carbene (NHC) complexes. A series of half-sandwich nickel(II) complexes, [Ni(R-NHC-n-Bu]XCp†] (Cp† = Cp, Cp*, X = Cl, I), bearing a N-bound n-butyl sidearm NHC ligands has been synthesized from the appropriate imidazolium halides and nickelocene or [Ni(acac)Cp*] as models for heterogenized versions of these complexes. All these complexes were fully characterized by standard spectroscopic techniques [1H and 13C{1H}NMR spectroscopy, 2D spectroscopy when appropriate, MS, and elemental analyses]. Furthermore, many representative complexes were the subject of single-crystal X-ray diffraction studies. All these complexes feature a two-legged piano stool geometry common for 18-electron MCp†L2 compounds with a trigonal planar geometry around the central nickel atom. The [Ni(Ar-NHC-n-Bu)ICp] compounds are highly active catalysts for the Suzuki cross-coupling of aryl bromides or chlorides with phenylboronic acid in the absence of any reductant or co-catalyst and show higher turnover frequencies (TOF) than seen in their closely related symmetric [Ni(Ar2-NHC)LCp†] counterparts. The origin of the improved stability of the in situ generated active species is discussed. A heterogenized version of these complexes onto alumina has been prepared by employing 3-(trialkoxysilylpropyl)imidazolium halides and tested in Suzuki cross-coupling. In the prospect of enhancing the longevity of the active species, unprecedented half-sandwich Ni(II) complexes bearing two different NHC ligands were prepared by displacement of the labile acetonitrile ligand from [Ni(Ar2-NHC)(CH3CN)Cp]+X- with a “free” NHC. The resulting cationic bis-(NHC)-nickel complexes [Ni(NHC)(NHC’)Cp]+X- show remarkable stability, and thus low acitivity in Suzuki couplings. The Ni– NHC bonds are particularly robust as can be demonstrated by the displacement of the Cp, and not of a NHC ligand, when these bis-NHC Cp complexes are protonated. The final chapter presents a novel reaction in which the base-promoted activation of sp3-hybridized C– H bonds a- to functional organic groups at Cp†Ni-NHC centres was achieved. The scope and breadth of this activation is demonstrated by the activation of acetonitrile, acetone and other ketones under relatively mild conditions to give a range of new nickel alkyls. A remarkable double activation of acetone was notably demonstrated. The activation of C–H bonds a-to nitriles in NHC-attached sidearms to give a series of new half-sandwich nickelacycles was also achieved. Possible mechanistic pathways for these reactions have been the subject of theoretical DFT analyses. Similarly to the bis-NHC species, the nickelacycles show great robustness of the NHC– and alkyl–Ni bonds
Citadelle, Cécilia. "Synthèses de nouveaux catalyseurs de ruthénium pour la métathèse des esters méthyliques d'huiles végétales." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00817291.
Full textCharra, Valentine. "Coordination of multidentate N-heterocyclic carbene ligands to nickel." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF019/document.
Full textThe purpose of this work was the synthesis of bis-NHC (N-Heterocyclic carbene) ligands, theformation of the corresponding silver(I), copper(I) and nickel(II) complexes and the assessment ofthe catalytic activity of the bis-NHC nickel(II) complexes in ethylene oligomerization. A series of new bis-NHC silver(I) and copper(I) complexes was synthesized. Five different synthetic routes were tested for the formation of nickel(II) bis-NHC complexes. The most significant results were obtained by transmetalation from the silver(I) iodide or bromide complexes
Longevial, Jean-François. "Synthèse et propriétés de complexes d'Or(I) de carbènes N-hétérocycliques fusionnés à des porphyrines." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT205/document.
Full textThis PhD work is devoted to the synthesis of porphyrins fused to imidazolium rings and their use as precursors of N-heterocyclic carbene ligands (NHC). Therefore, these compounds possess two coordination sites, the internal (the macrocycle) and the external (the NHC ligand) ones, allowing the synthesis of dinuclear complexes. This study is mainly centered on the synthesis of metalloporphyrins conjugated with peripheral gold(I) complexes such as [(NHC)AuCl]. In view of applications in photodynamic therapy (PDT), the functionalization of these complexes by carbohydrates was achieved through the substitution of chloride ligands of peripheral gold(I) complexes. Biological tests on cell cultures show a clear potentialization of the photodynamic properties of the photosensitizers bearing mannose ligands bound to gold(I). Following this study, the synthesis of porphyrins fused to two imidazolium rings was achieved allowing for the first time the synthesis of trinuclear species such as Au/M/Au (M = inner metal in the porphyrin core) with different geometries. These compounds open interesting perspectives in view of obtaining photosensitizers having two carbohydrates at their periphery. Moreover, it was shown that trinuclear species such as Au/Zn/Au can be used as molecular building-blocks for the synthesis of organometallic polymers in view of applications in (photo)catalysis
Bouché, Mathilde. "Carbene-platinum conjugated : novel anticancer complexes." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE013.
Full textAlthough platinum-based anticancer drugs are well established, several shortcomings have raised concerns, namely their toxicity and resistance mechanisms. Therefore, improved anticancer drugs are strongly awaited to substitute drugs currently used in clinics. Remarkably, the combination of N-Heterocyclic Carbenes (NHCs) to platinum has recently demonstrated very promising results as anticancer agents. In the aim to access novel drugs, this work emphasizes several structural modifications to improve the cytotoxicity and lower side effects. One strategy developed herein focus on the introduction of pnictogens by ligand exchange to access a synergistic effect. Otherwise, efforts mainly focused on NHC-platinum(IV) complexes from their synthesis to stability investigation and anticancer activities and mechanism of action. Finally, the combination of NHC-Pt drugs to nanodelivery devices has been investigated in order to improve both their biocompatibility and selectivity toward cancer cells
Citadelle, Cécilia. "Synthèses de nouveaux catalyseurs de ruthénium pour la métathèse des esters méthyliques d’huiles végétales." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10083/document.
Full textThe development of efficient ruthenium based catalysts has contributed to the development of olefin metathesis. This reaction catalyzed by tungsten, rhenium or molybdenum complexes, was applied, until now, to non-fonctionalized olefins. The use of ruthenium precursors allowed to broaden range of applications of olefin metathesis owing to their high tolerance to various organic functions. Indeed, methyl esters of vegetable oils can be converted into chemical base by metathesis in the presence of ruthenium based catalysts. In this study, we report ruthenium complexes reactivities for ethenolysis of methyl oleate as well as the design and the characterization of new systems. We describe the synthesis of new ruthenium catalysts containing cyclic alkyl(amino)carbenes and the evaluation of their performances. We show that these precatalysts display interesting catalytic properties for the ethenolysis of methyl oleate. Modifications of the carbenes ligands architecture provide the possibility to create novel catalysts as the functionalization of the isopropoxybenzylidene ligand which allowed immobilization of catalysts in ionic liquid. Besides, attempts to coordinate other ligands, such as fluorenylidène and silylene, able to afford active complexes will be discuss
Henrion, Mickaël. "Synthesis and homogeneous catalytic applications of nickel(II)-N-heterocyclic carbene complexes." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF057/document.
Full textA detailed study has been conducted on organometallic compounds of N-heterocyclic carbenes (NHC) of nickel(II), in particular on half-sandwich nickel(II)−NHC complexes. These complexes showed unprecedented catalytic activity in homogeneous catalysis, especially in the α-arylation of acyclic ketones, where catalyst loadings as low as 1 mol% could be used. Mechanistic experiments suggest that radicals are implied. Furthermore, these half-sandwich complexes proved to be efficient pre-catalysts in the hydrosilylation of carbonyl compounds and imines, allowing the reduction processes to proceed under mild reaction conditions. During the course of these studies, a half-sandwich nickel−hydride intermediate that probably acts as the true pre-catalyst was isolated. Remarkably, the synthesis of new Ni−NHC complexes led to a methodology for cyclopentadienyl ligand substitution in stable 18-electron alkyl,NHC−Ni derivatives. Finally, the use of less common NHC ligands, such as NHCs possessing a malonate backbone, or else, the use of cyclic (alkyl)(amino) carbenes, led to the isolation of new nickel−carbene complexes, which gave encouraging preliminary catalytic results
Marrot, Sébastien. "Carbènes N-Hétérocycliques : Des catalyseurs en chimie des silicones. Carbodiphosphoranes cycliques : Synthèse, coordination et réactivité." Phd thesis, Toulouse 3, 2007. http://www.theses.fr/2007TOU30037.
Full textIn a first chapter, we are interested in the use of N-Heterocyclic Carbenes like nucleophilic organic catalysts for ring opening polymerization of octamethylcyclosiloxane and for reactions of polycondensation. In a second chapter, we carry out a bibliographical review on compounds presenting two cumulated ylides functions : carbodiphosphoranes. In a third chapter, we present the synthesis and the coordination of new cyclic carbodiphosphoranes. They are recognized to be strong s-donor ligands for transition metals. In a fourth chapter, we study the thermolysis of one of these compounds which leads by rearrangement to the formation of a 1,2l5-azaphosphète. A theoretical study highlights an inter-conversion between carbodiphosphoranes and disphosphinocarbenes
Rosa, Lourenço de Pina Cardoso Bernardo. "Structure of cationic CNHC,Calkyl nickelacycles and their activity in the catalytic functionalization of the C–H bonds of azoles." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF033/document.
Full textThis thesis develops the study of nickel(II) complexes bearing N-heterocyclic carbene ligands (NHC) in two axes: the synthesis and characterization of nickelacyclic complexes with a carbon-carbon chelating ligand (CNHC,Calkyl); and their catalytic activity in the construction of carbon-carbon bonds (Csp2–Csp2/Csp3) of 1-chalcogene-azoles by carbon-hydrogen (C–H) bond functionalization. A series of cationic CNHC,Calkyl-Ni(II) metallacyclic acetonitrile adducts was synthetized by the removal of a cyclopentadienyl ligand from parent 18 valence electron half-sandwich nickelacycles. The cationic complexes were determined to exist as rare coordinatively and electronically unsaturated T-shaped 14 valence electron Ni(II) species, in the solid state. Application of these new complexes to the cross-coupling of benzothiazole with iodoarenes proved to be a successful strategy in Csp2–Csp2 bond formation, by the combination of a stabilizing metallacyclic scaffold with labile ligands. The discovery of a half-sandwich Ni(II)-(NHC)-(benzothiazolyl) species, inactive in the arylation of benzothiazole, but active for the cross-coupling of benzothiazole with iodoalkanes shows the first example of benzothiazole Csp2–Csp3 bond construction with a Ni(II)-NHC catalyst
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.
Full textThis 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
Kong, Lingyu. "De ligands NHCs prochiraux à des complexes métal-NHC énantiopurs : nouvelles perspectives pour la catalyse asymétrique." Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0502.
Full textN-heterocyclic carbenes (NHC) are recognized to be excellent ligands towards transition metals ™. In this manuscript, the first chapter is dedicated to a non-exhaustive presentation of the various approaches of the literature which have been used to design chiral NHCs efficient in enantioselective catalysis. As a prelude of the second chapter, the new concept lies on the formation of an axis of chirality during the coordination between the NHC ligand and the transition metal. This chapter is dedicated to the synthesis of complexes with a C1 symmetry. Various imidazolium salts, have been synthesized and then used to generate palladium complexes. These complexes have been obtained in a enantiopurically form thanks to a chiral HLPC resolution at a preparative scale. These homochiral complexes were firstly subjected to studies aiming the investigation of their chiroptic properties and the determination of their rotation barriers values. The concept was then successfully extended to the synthesis of gold- and copper-based complexes. Homochiral copper-NHC complexes were found of particular importance since their applications in catalysis allowed to reach good enantioinductions and as NHC transfer reagents brought some experimental proofs on the transmetalation process. The third chapter disclosed the works that have been done on the preparation of heterochiral NHC-TM complexes possessing a C2 symmetry. Various symmetric imidazolium salts have been synthesized and then used to form the corresponding palladium-based complexes. Homochiral complexes were found displaying good activities for α-arylation of amides and excellent enantioselectivities (up to 98% ee)
Tang, Shun. "Cycloisomérisations catalysées par les sels du gallium et les complexes NHC-Gallium(III)." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112271.
Full textRecently, in order to develop alternative activation methods for Pi-systems in homogeneous catalysis instead of employing expensive and toxic noble metal catalysts, first row transition metals and main group metal complexes have attracted great attention. This thesis is a contribution to it, and we focus on gallium chemistry. There are three main aspects dominating this thesis: gallium(III) halides, well-defined gallium(III) complexes bearing N-heterocyclic carbenes (NHCs), and -systems activation in catalysis.The thesis is divided into three chapters. Chapter I provides an overview of the field of organic synthesis involving gallium(III) compounds, focusing on their use as - or -Lewis acids.In Chapter II, we expose our attempts to exploit the catalytic potential of gallium(III) chloride in a novel tandem cycloisomerization/Friedel-Crafts reaction. A section dedicated to the study on GaCl3-catalyzed alkyne hydration is also provided.Chapter III begins with a description of the synthesis of a series of gallium(III) complexes bearing various NHCs as ligands in order to overcome the limitations of gallium(III) halides in catalysis. Next, methodology studies on the tandem process involving 1,6-arenynes with the neutral and cationic gallium(III) complexes are described. The evaluation of scission kinetics for catalysts, substrates variation and influence of counteranions are discussed. In addition, efforts towards the asymmetric version of this tandem transformation and some other cyclizations are also presented.The concluding chapter reiterates the most important results obtained in the body chapters of the thesis. To conclude, the future directions for the research on the use of the NHC-gallium(III) complexes are discussed
Natarajan, Nallusamy. "Ligands build on macrocyclic platforms : can the macro cyclic unit influence the catalytic properties ?" Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF052.
Full textThis thesis describes the synthesis of a series of compounds built on conical resorcin[4]arene and calix[4]arene platforms: a) diphosphites derived from optically active binol, in which the phosphite moieties have been grafted to the wider rim of the generic cones. These ligands were assessed in asymmetric hydroformylation of vinyl arenes and led to high iso selectivity with good to excellent enantiomeric excess; b) N-heterocyclic carbenes bearing either one or two cavitand moieties and their use for the synthesis of [NiXCpL] complexes (X = Br or Cl, Cp = cyclopentadienyl, LH = NHC) in which the NiCp moiety has been supramolecularly trapped in a resorcinarene bowl. These complexes were found active in ethylene dimerization; c) bulky triazolium salts with one or two resorcinarene substituents that were found suitable for the synthesis of complexes with abnormal NHCs. The latter were tested in palladium-catalysed Suzuki-Miyaura cross-coupling of bulky aryl chlorides with sterically hindered aryl boronic acids. Better activities were observed with the sterically less hindered triazolium salt, which bears a single resorcinarene substituent. Its higher efficiency arises from a higher substrate accessibility in the resulting catalytic intermediates as well as the presence of flexible pentyl groups that may interact with the metal centre so as to facilitate the reductive elimination step
Zheng, Jianxia. "Earth-abundant metal complexes for catalyzed hydroelementation." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S148/document.
Full textThis research work deals with the use of the catalysts based on the earth-abundant transition metals of the first row of the periodic table, such as Mn, Fe, and Ni, for hydroelementation reactions. First of all, the hydrosilylation of aldehydes and ketones was accomplished using a simple Ni(OAc)₂ 4H₂O/PCy₃ catalytic system with the inexpensive and stable silane PMHS as the hydride source. The reductive amination of aldehydes with amines was also achieved with the same catalytic system and TMDS, as the silane. Second, the efficiency of manganese half-sandwich complex CpMn(CO)₂(IMes) was exemplified for the reduction of aldehydes and ketones in the presence of Ph ₂ SiH ₂ (1.5 equiv.) under UV irradiation at room temperature. Still with manganese, the challenging transformation of carboxylic acids to aldehydes was performed using commercial Mn₂ (CO)₁₀ and Et₃SiH. Third, the methylation of the secondary amines with dimethyl carbonate as an alternative and safe C1 source was demonstrated under mild conditions with [CpFe(CO)₂(IMes)]I as the catalyst. Then, the hydroboration of functionalized alkenes and alkynes was catalyzed by an iron(0) carbonyl complex Fe(CO)₄(IMes) under UV irradiation. Finally, the hydroboration reaction was successfully extended to the reduction of CO₂ to methoxyboranes with Fe(CO)₃[P(OPh)₃]₂ as the catalyst and the borane sources, such as HBpin, HBcat or 9-BBN
Wang, Chang-Sheng. "Selective catalytic C(sp²)–H and C(sp³)–H bond functionalizations for the synthesis of phosphorus and nitrogen containing molecules." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S106/document.
Full textIn the first chapter, we have developed an efficient approach for the fast modification of arylphosphine oxides using ruthenium(II)-catalyzed C–H bond functionalization with alkenes. Interestingly, we have found that the selectivity of the reaction, namely alkylation versus alkenylation, is depending on the reaction pH. The reduction of the phosphine oxide allows the formation of aryl phosphines bearing a flexible pendent carboxylate. In the second objective, a copper-catalyzed oxidative C(sp3)–H/N–H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp3)–N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalyst.In a third part, benzylic C(sp3)–H acyloxylation of 2-alkylpyridine, 2-alkylpyrazine and 2-alkylthiazole compounds was achieved using simple aldehydes via a copper-catalyzed tandem reaction, involving oxidative esterification followed by O-atom transfer. Finally, pyridin-2-ylmethyl tosylate derivatives are obtained in high yields from 2-alkylpyridine N-oxides via a [3,3]-sigmatropic rearrangement of the adduct between 2-alkylpridine N-oxides with benzenesolfonyl chlorides. Moreover, alkylnitrones also underwant [3,3]-sigmatropic rearrangement to give α-tosylated ketones after hydrolysis
Schnee, Gilles. "Synthèse et réactivité de nouveaux complexes des métaux du groupe 13 portés par des ligands carbènes N-hétérocycliques." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAF053/document.
Full textAt the beginning of this work, few studies had been performed on the complexation of N-heterocyclic carbenes with oxophilic metals, in high oxidation states such as group 13 metals. The synthetic routes optimization has extended the number of complexes-type NHC-MIII (M = aluminum, gallium and indium), and the corresponding cationic complexes. The combination of these precursors with sterically congested NHCs allowed the observation of unprecedented reactivities (abnormal complexes, Frustrated Lewis Pairs, N-heterocyclic dicarbenes). In a second step, the unusual reactivity of NHC ligands has allowed the isolation of analogues of the Tebbe’s reagent, formed to be very active in the methylenation of carbonyl compounds
Li, Jihui. "Copper-Catalyzed Domino C-N Bond Formation for Synthesis of N-Containing Compounds (Benzimidazoles, Imidazoles, and Guanidines) - Approach toward Total Synthesis of Natural Product Raputindoles." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112130.
Full textThis thesis consists in three parts: bibliographic background, copper-catalyzed reactions for synthesis of N-containing compounds, approach to the synthesis of raputindoles.The first part introduces the domino reactions and their applications, then, copper-mediated reactions for construction of C-N bond formation are reviewed including Ullmann, Goldberg and Chan-Lam coupling, oxidative C-H activation/C-N formation, insertion of nitrenes and carbenoids, and hydroamination of multi-C-C bonds. This can be used as guides to design domino reaction. Following these copper-mediated single C-N bond formation reactions, recent developments of copper-catalyzed domino reactions for synthesis of heterocycles are described.The second part can be divided into three sections: 1) synthesis of benzimidazoles, 2) synthesis of imidazoles and 3) synthesis of guanidines. Each section summarizes the existing methods used for their synthesis. Following it, our synthetic work involving copper-catalyzed C-N bond formation domino reactions is discussed in detail. Our objectives include the synthesis of benzimidazoles through copper-catalyzed sequential reaction of benzamidines and boronic acids, synthesis of imidazoles via copper-catalyzed domino reaction of benzamidines and acetylenes, and synthesis of guanidines and 2-aminobenzimidazoles by Cu-catalyzed three-component reaction of cyanamides, boronic acids and amines. These copper-catalyzed domino reactions show high efficiencies from readily available and simple starting materials.The last part is about the total synthesis of raputindoles. The structure and bioactivities of raputindoles and key reactions for the total synthesis of raputindoles are introduced first, the synthetic strategies are then proposed on basis of relative synthetic methods. The key reactions we use for the synthesis of raputindoles are iridium catalyzed [3+2] annulation of o-formylarylboronic acids and 1,3-dienes, Leimgruber-Batcho indole synthesis, transition-metal catalyzed SN2 substitution and alkylborylation-protondeborylation. According to the three strategies we proposed, lots of relative reactions were investigated. The results show that it is possible to synthesize the raputindole molecules based on the iridium catalyzed [3+2] annulation of 2-formylarylboronic acids and 1,3-dienes
Legrand, François-Xavier. "Nouveaux transporteurs et ligands à base de cyclodextrine pour les processus de catalyse organométallique en milieu aqueux." Thesis, Artois, 2010. http://www.theses.fr/2010ARTO0405/document.
Full textThe development of clean chemical synthesis currently mobilizes a wide range of scientific teams. Thereby, the aqueous phase organometallic catalysis is a process that uses a green solvent par excellence, water. In this type of processes, the organometallic catalyst generally gets water-soluble thanks to the use of water-soluble phosphanes. However, these systems aren't really active with hydrophobic organic substrates. In order to avoid this problem, we can use cyclodextrins to promote mass transfer between the organic phase and the aqueous phase. However, the formation of an inclusion complex between the water-soluble phosphane and the cyclodextrin can also be created, generating a decrease in the catalytic activity due to the poisoning of the macrocyclic cavity, and also a modification of the catalytic system's nature leading to the formation of less selective catalytic species. Studying various catalytic systems which involve chemically modified cyclodextrins enabled the creation of catalytic systems the properties of which are kept. Otherwise, another approach in the use of cyclodextrins in aqueous phase organometallic catalytic processes enabled the synthesis of cyclodextrin-based ligands where the cyclodextrin plays the role of hydrophilic group. In this case, not only does it ensure the water-solubility of the ligand, but the cyclodextrin also gives molecular recognition properties to these ligands, which can lead to catalytic systems which possess specific properties
Elie, Margaux. "Développement de nouveaux complexes organométalliques de métaux de transition polyvalents pour la scintillation et la chimie médicinale." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC227.
Full textNew cationic copper(I) complexes of general formula [Cu(NHC)(N^N)][X] and [Cu(P^P)(N^N)][PF6] were developed with 6-membered-ring 2,2’-bis-pyridyl derivatives as ligand. These complexes exhibited blue (420 nm) to green (520 nm) emissions in solid state, with large Stokes shifts and photoluminescence quantum yields up to 0.86. Furthermore, the emission of the [Cu(NHC)(N^N)][X] complexes via a thermally activated delayed fluorescence (TADF) was demonstrated. The first plastic scintillators incorporating copper(I) complexes and detecting gamma radiations were obtained with [Cu(P^P)(N^N)][PF6] complexes. Application of the [Cu(NHC)(N^N)][X] complexes to the LEC technology led to the first copper(I)-based blue emitting device. In the last chapter, we also demonstrated that copper(I) complexes [Cu(NHC)(N^N)][X] bearing a 2,2’-dipyridylamine as N^N ligand exhibited high cytotoxycity against different cancer cells lines. These complexes paved the way for the design of a new type of copper(I) anti-cancer agents with the opportunity to increase the selectivity against cancer cells via a vectorization of the N^N ligand. The versatility of these copper(I) complexes demonstrated in this work relied on the easy to handle and highly modular 2,2’-bis-pyridyl ligands
Vast, Nathalie. "Etude ab initio des propriétés physiques des matériaux." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00440923.
Full textHoltz-Mulholland, Michael. "Synthesis of transition metal N-heterocyclic carbene complexes and applications in catalysis." Thèse, 2014. http://hdl.handle.net/1866/11407.
Full textA new class of C1-symmetric N-heterocyclic carbene (NHC) ligands has been developed. The new ligands exploit a biaryl methyne as a chiral relay, and an N-methyl group as a reactivity controlling element. The precursors for the new ligands were synthesized via a modular scheme that allows for facile diversification. Several of the new ligands were installed onto both copper and gold, generating mono N-heterocyclic carbene transition metal complexes. The new C1-symmetric copper complexes were tested as catalysts for the synthesis of binaphthols via the oxidative coupling of electron poor 2-naphthols. The new C1-symmetric ligands afforded higher yields than their C2-symmetric counterparts. During the course of the optimization, small molecule additives were found to modulate the reactivity of the copper catalyst. Pyridine additives, such as 2-picoline, were found to induce low to moderate enantioselectivity in the oxidative coupling reaction, while diethylmalonate was found to improve the reaction yield without affecting the selectivity. The malonate additive was employed in the catalytic oxidative heterocoupling of electronically dissimilar 2-naphthols. The electron-rich coupling partner is normally added in a large excess due to its tendency to degrade. When the malonate additive is used, the coupling partners can be used in equimolar quantities. The discovery resulted in the development of a general protocol for the additive assisted aerobic oxidative heterocoupling of electronically dissimilar 2-naphthols.
Fournier, Pierre-André. "Préparation et caractérisation de nouveaux catalyseurs de métathèse asymétrique." Thèse, 2007. http://hdl.handle.net/1866/7832.
Full textSavoie, Jolaine. "Développement d'une méthode d'alkylation pour la préparation de ligands carbènes N-hétérocycliques C₁-symétriques et synthèse de nouveaux catalyseurs pour la métathèse d'oléfines." Thèse, 2008. http://hdl.handle.net/1866/7829.
Full textLe, Gall Tatiana. "Decarboxylative Generation of Carbenes for the Synthesis of N-Heterocyclic Carbene Copper(I) Complexes - Applications in the Oxidative Coupling of 2-Naphthols." Thèse, 2011. http://hdl.handle.net/1866/6899.
Full textThe present thesis describes the synthesis and utility of NHC-Cu complexes. First, the synthesis of N-heterocyclic carbene (NHC) copper complexes via the decarboxylative generation of carbenes is presented. Indeed, literature precedents reported that imidazol(in)ium-2-carboxylates may be used as carbene precursors under thermolytic conditions. As such, the present study demonstrates how zwitterionic carboxylates may be utilized in the formation of both mono- and bis-NHC Cu complexes with various substitution patterns and counterions. Secondly, the NHC-Cu complexes were evaluated for the synthesis of 2,2’-binaphthols via the oxidative coupling of naphthol derivatives. The objective of the study was to investigate how structural variations to various NHC-Cu catalysts may generate a more efficient catalytic process. Effects of the structure of the catalyst on the coupling reaction have been studied by varying the number of NHC ligands coordinating to Cu, as well as the nature of the NHC ligand substituents and the counterions.