Dissertations / Theses on the topic 'Catalytic hydroamination'
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Shasha, Adelle. "Metal-Catalysed Hydroamination." Science. School of Chemistry, 2007. http://hdl.handle.net/2123/1710.
Full textThis thesis describes the synthesis of terminal and internal amino and amidoalkynes and their hydroamination (cyclisation) catalysed by the complex (bis(N-methylimidazol-2-yl)methane)dicarbonylrhodium(I) tetraphenylborate (1). A series of analogous palladium complexes were also prepared and investigated for catalytic hydroamination. The scope of the rhodium(I) complex (1) for the intramolecular hydroamination of more complex amino and amidoalkyne substrates was investigated. This was made possible with the synthesis of aliphatic substrates, namely, 4 pentyn 1 amide (3) and 5 hexyn 1 amide (4) and a number of aromatic substrates, namely, 1, 4 diamino-2, 5 diethynylbenzene (5), 1, 4-diamino-2, 5 bis(phenylethynyl)benzene (6), 2, 3-diamino-1, 4-diethynylbenzene (7), 2, 3-diamino-1, 4-bis(phenylethynyl)benzene (8), 1, 5-bis(acetamido)-2, 4-diethynylbenzene (9), N-(acetyl)-2-ethynylbenzylamine (10) and N-(acetyl)-2-(phenylethynyl)benzylamine (11). The rhodium(I) complex (1) catalytically cyclised the aliphatic 4 pentyn 1 amide (3) regioselectively to the 6 membered ring, 3, 4 dihydro 2 pyridone (64) as the sole product. Attempts to cyclise 5 hexyn 1 amide (4) to produce either the 6 or 7 membered ring were unsuccessful. Compounds 5, 6, 7 and 8 were doubly cyclised to 1, 5 dihydro pyrrolo[2, 3 f]indole (71), 1, 5-dihydro-2, 6-diphenyl-pyrrolo[2, 3 f]indole (73), 1, 8-dihydro-pyrrolo[2, 3 g]indole (74) and 1, 8-dihydro-2, 7-diphenyl-pyrrolo[2, 3 g]indole (75) respectively. The aromatic amides with terminal acetylenes 9 and 10 cyclised to give 1, 7 diacetyl pyrrolo[3, 2 f]indole (76) and N (acetyl) 1, 2 dihydroisoquinoline (77) respectively. However, attempts to cyclise 11 were unsuccessful. Thus the rhodium(I) complex (1) successfully catalysed via hydroamination both terminal and internal acetylenic amine and amide substrates, to give pyridones, indoles and isoquinolines. Cationic and neutral palladium complexes incorporating the bidentate heterocyclic nitrogen donor ligand bis(N-methylimidazol-2-yl)methane (bim; 2) were synthesised: [Pd(bim)Cl2] (15), [Pd(bim)2][BF4]2 (17) [Pd(bim)(Cl)(CH3)] (14), [Pd(bim)(CH3)(NCCH3)][BF4] (16). All of the complexes were active as catalysts for the intramolecular hydroamination reaction, using the cyclisation of 4 pentyn 1 amine (21) to 2 methyl 1 pyrroline (22) as the model test reaction. Percentage conversions, turnover numbers and reaction profiles for each complex were compared to the rhodium(I) complex (1). These studies have shown that the catalytic activity was not significantly dependent on the bim donor ligand or the choice of metal. Substitution of the bim (2) ligand with the COD ligand and the use of methanol as the solvent did impact significantly on the efficiency of the hydroamination reactions.
Shasha, Adelle. "Metal-Catalysed Hydroamination." Thesis, The University of Sydney, 2006. http://hdl.handle.net/2123/1710.
Full textCourtney, Sarah Turner. "Trifluoromethylated zirconium amidate complexes : new directions for the catalytic hydroamination of alkenes." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/9704.
Full textLau, Ying Yin. "Catalytic synthesis of N-heterocycles and alpha-alkylated amines by hydroamination and hydroaminoalkylation." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/60156.
Full textScience, Faculty of
Chemistry, Department of
Graduate
Moran, Erik John. "Novel Synthetic Routes to Complex Amines: the Catalytic Hydroamination of Alkynes and Hydroimination of Allenes." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/28036.
Full textNSF (CHE-1301409 to R.M.) and ND-EPSCoR (RII-1330840)
Wixey, James S. "Novel calcium complexes applied to intramolecular hydroamination catalysis." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/37858/.
Full textThomson, Robert Kenneth. "Amidate complexes of the group 4 metals : sythesis, reactivity, and hydroamination catalysis." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1344.
Full textBrown, Adam Ross. "I. Engaging Cationic Intermediates in Asymmetric Catalysis: Enantioselective Reactions of Carbenium Ions and N,N-Dialkyliminium Ions II. Enantioselective Catalysis of the Cope-Type Hydroamination by H-Bond Donors." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11009.
Full textChemistry and Chemical Biology
Loiseau, Francis. "Cope-type Hydroamination of Alkenes with Hydroxylamines and Hydrazines - Scope and Mechanism." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23794.
Full textBilodeau, Didier Alexandre. "Exploiting Intramolecularity: Exploring Aldehyde-Catalyzed Intermolecular Hydroaminations and Mixed Aminal Chemistry." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37100.
Full textLepori, Clément. "Complexes de fer(II) et de cobalt(II) de basse coordinance : synthèses, caractérisations et applications en réaction d’hydroamination des alcènes." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS509.
Full textThe nitrogenous units are present in many molecules of pharmaceutical interest. The traditional synthesis methods of these units range, for example, from the nucleophilic substitution of amines on alkyl halides to reductive amination of the carbonyl compounds. These methods, although effective, nevertheless require stoichiometric amounts of reagents to be applied and often generate large amounts of waste. One of the challenges of modern organic chemistry is to develop new methods of synthesizing these more economical and environmentally friendly patterns by producing the lowest waste rate possible. The direct addition of an amine to an unactivated carbon-carbon double bond known as the alkene hydroamination reaction is a very promising approach for the development of an alternative synthesis methodology for these compounds. Indeed, in this reaction, all the atoms of the starting substrate are transferred to the product thus considerably reducing the waste produced. In addition, the amines and olefins employed are relatively inexpensive, abundant and varied reagents. Nevertheless, this simple transformation generally requires the use of a catalyst. In the literature, the hydroamination reaction of alkenes has been studied using alkali metal, alkaline earth, rare earth and transition metal complexes as catalysts. At the beginning of this project there were no examples of the hydroamination reaction of alkenes involving unprotected primary amines catalysed by iron or cobalt complexes. In this context, our team was interested in the reactivity of iron (II) and cobalt (II) complexes of low valence stabilized by β-diketiminate ligands. These complexes have proved to be excellent catalysts for promoting the hydroamination reaction of unprotected primary amines bound to non-activated alkenes.In a first step, the syntheses of the iron (II) and cobalt (II) complexes stabilized by β-diketiminate ligands as well as their applications in cyclohydroamination reaction of the unprotected primary amines will be presented. In addition, advanced mechanistic studies will clarify the mechanism of the reaction, which is proposed to go through a key elementary 1..2 migratory insertion leading to the formation of a carbon-nitrogen bond.In a second step, the influence of the electron and steric properties of the ligands on the reactivity in the hydroamination reaction of the alkenes of the iron (II) alkyl complexes will be studied. We will focus particularly on complexes stabilized by asymmetric β-diketiminate ligands or iminoanilides. The crystallographic data of the solid state complexes will then make it possible to rationalize the variations of reactivities of these various complexes.Finally, the iron (II) and cobalt (II) complexes synthesized above will be exploited to develop new reactivities in oxidation reactions, oxidative amination or the creation of a nitrogen-silicon bond by a dehydrogenating coupling
Arrowsmith, Merle. "Intramolecular hydroamination of aminoalkenes with group 2 precatalysts : mechanistic insights and ligand design." Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538274.
Full textShaffer, Andrew R. "Synthesis, Reactivity, and Catalysis of 3-Iminophosphine Palladium Complexes." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1248288981.
Full textChapurina, Yulia. "Nouveaux complexes chiraux d'yttrium pour l'hydroamination intramoléculaire asymétrique des aminoalcènes." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112219.
Full textChiral nitrogen-containing heterocycles represent an important class of biologically active compounds. The asymmetric intramolecular hydroamination perfectly matches the concept of sustainable chemistry and allows the formation of new nitrogen-carbon bonds in an ideal atom efficiency and economy, starting from non activated substrates. The development of catalysts for formation of enantioenriched pyrrolidines and piperidines derivatives remains however a challenging task. The topic of this dissertation is the study of new easily accessible chiral yttrium binaphthylamide complexes and their application for promoting the hydroamination/cyclisation of primary amines tethered to sterically demanding alkenes. Chiral binaphthylamido alkyl ate yttrium complexes have been investigated. These catalytic systems have been prepared by a facile in situ stoichiometric reaction of a well-known yttrium precursor [Li(THF)4][Y(CH2SiMe3)4] with a variety of chiral substituted (R)-binaphthylamine ligands. These chiral heteroleptic complexes are shown to be efficient catalysts for the enantioselective intramolecular hydroamination of 1,2-disubstituted aminoalkenes leading to the formation of five and six-membered N-heterocycles. Yttrium catalysts prepared from (R)-N-anthrylmethyl-binaphthylamine ligand H2L13 and (R)-N-para-substituted benzyl ligands H2L4 or H2L6 proved to be the most enantioselective catalysts at 70-110°C for the hydroamination/cyclisation of challenging aminoalkenes. An enantiomeric excess value of 77 % was indeed disclosed as the highest value reported so far for the asymmetric intramolecular hydroamination of amines tethered to 1,2-disubstituted alkenes. The first examples of asymmetric intramolecular hydroamination of 1,1,2-tri-substituted aminoalkenes have been reported. The alkyl ate yttrium complexes produced the heterocyclic compounds with enantioenriched quaternary centres under harsher reaction conditions than the cyclisation of the corresponding 1,2-disubstituted alkenes, and with promising enantioselectivities of up to 55 %.The neutral alkyl yttrium complexes containing one molecule of lithium chloride [{(R)-C20H12(NSiMe3)2}Y{CH2SiMe3}{LiCl(THF)2}] and [{(R)-C20H12(NC5H9)2}Y{CH2SiMe3}{LiCl(THF)2}] have been prepared and compared with the same complexes lacking LiCl. They have been revealed as efficient catalysts for intramolecular hydroamination of terminal aminoalkenes
Guimond, Nicolas. "Part A: Rhodium-catalyzed Synthesis of Heterocycles / Part B: Mechanistic Studies on Tethering Organocatalysis Applied to Cope-type Alkene Hydroamination." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23222.
Full textBarber, David M. "The development of nitro-Mannich/hydroamination cascades for the synthesis of substituted N-heterocycles." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:18e7c533-3789-4800-9813-1d5c7bb4e4ea.
Full textRuch, Aaron A. "Design of New Monodentate Ligands for Regioselectivity and Enantioselectivity Tuning in Late Transition Metal Catalysis." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849723/.
Full textBahri, Janet. "Nouvelles méthodes d'hydroamination d'alcynes." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2015. http://www.theses.fr/2015ENCM0019/document.
Full textIn this thesis, we developed the hydroamiantion arylacétylènes reaction in the presence of some aliphatic secondary amines. At first, we could show that this reaction can be catalyzed by various copper salts. The catalytic use of CuCN allowed the regional training and sétéréosélective enamines derived from anti-Markovnikov addition type orientation isomerism (E). Developed conditions have not allowed the purification of the observed enamines. For this reason a reduction in the presence of the reducing agent NaBH3CN was performed in order to isolate the corresponding amines. The catalytic use of CuCl enabled in turn, under certain conditions, the regio-and stereoselective synthesis of 1,3-dienes (1E, 3E) -1,4-disubstituted oxanilides. The electronic nature of substituents of the aromatic rings alkynes employed played a major role as regards the chemoselectivity of the reaction.Secondly, we concentrate developed to improve conditions and find other more efficient ways, cheaper and greener, we were able to show that the test reaction can also be carried out only in the presence ethylene glycol used as solvent and the reaction promoter. This method allows direct access to enamines from the addition anti-Markovnikov orientation type of isomerism (E) with excellent isolated yields without the need to purify the resulting enamines
Germain, Stephane. "Réaction d'hydroamination régiosélective catalysée par des sels de lithium ou par des complexes d'yttrium, de zirconium ou d'hafnium." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112272/document.
Full textThe addition reaction of an amine across a carbon-carbon double bond, the so-called hydroamination reaction, is one of the most efficient method for the formation of value-added nitrogen-containing compounds. During the last decade, the interest of the scientific community has led to the development of a large number of efficient catalysts for this transformation. Nevertheless many challenges remain. Indeed only a few of the reported catalysts have a wide range of applications or possess good activities in the field of the intermolecular version of the reaction, less favored both kinetically and thermodynamically. In these work the mechanism of intramolecular HA reaction catalyzed by an yttrium complex has been determined by a kinetic study. During the latter a partial order of 1 for the catalyst and a reverse order in substrate were measured. The potential in the HA reaction of several catalytic systems based on different metals was evaluated. Tridentate complexes of zirconium or hafnium in their neutral or cationic form showed good activity in the cyclization reaction of several aminoalkenes bearing primary or secondary amines. The use of an yttrium complex allowed a regiospecific access to wide range of arylethylamines by catalysis of the intermolecular HA reaction between weakly hindered secondary amines and styrene derivatives. A structure-activity study was conducted pointing the noteworthy activity of the yttrium complex in the intermolecular HA reaction with 2-vinylpyridine, which also allowed an application in a tandem di-hydroamination reaction. Finally, a simple procedure for catalyzing the intermolecular HA reaction of styrene derivatives has been developed by using a lithium salt active at room temperature
Iali, Wissam Nabil. "Iridacycles à chiralité planaire : concepts, synthèses et applications." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAF020/document.
Full textOne of the main research domain in the laboratory of «Synthèse Metallo-Induites» consists in the development of new planar chiral metallacycles complexes. The challenge of this thesis was the development of new selective approaches for the synthesis of new cationic and neutral planar chiral metallacycles complexes in which the chelated metal is a pseudotetrahedral stereogenic center.The thesis project was initiated by the study of the unusual cycloruthenation of a 2-phenylpyridine ligand which was able to produce a tris-cationic homobimetallic planar chiral ruthenacycle as secondary product in a one step reaction starting from simple substrates. This type of homobimetallic product is only formed when a strong electrodonationg group as NMe2 is present on the starting ligand. In view of this result, we engaged a systematic study by synthesizing new planar chiral iridacycles compounds. The positively charged metal fragments (Cp*Ir2+, Cp*Ru+) and neutral (Cr(CO)3) may p-coordinate the electronic rich aryl fragment of the iridacyclic compound by virtue of the coulombic imbalance in the coordination sphere of the chelated metal center. One of the unexpected consequence of this research is the emergence of the concept ″deported constitutional chirality″, which appeared during the study of the conformational behaviour of an endodicationiciridacyclic complex where the methyl groups carried by the N,N-dimethylamino substituent diastereotopicity.To this fundamental quest for selectivity an explanation of the catalytic proprieties of our complexes was added. They were found to be good precatalysts for the promotion of the water oxidation catalysis and to be promising catalysts for tandem hydroamination/hydrosilation of terminal alkynes
Gómez-Orellana, Seguín Pablo. "Estudio Mecanístico de reacciones de aminación y de hidroaminación." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667362.
Full textIn this thesis, two reactions have been studied: C-N bond formation, hydroamination of olefins and Buchwald-Hartwig amination. The hydroamination reaction studied is the cyclohydroamination alkenylamines catalyzed by a complex of β-diketiminatocobalt (II). This reaction presents the peculiarities of being the first hydroamination by a cobalt complex without protective groups in the amine and without needing additional reagents. It has been proposed a mechanism for this reaction. Furthermore has been analyzed the effect of the substituents on the quaternary carbon, and finally the electronic state of the metal in the reaction has been studied. The amination reaction studied is the Buchwald-Hartwig amination catalyzed by a Pd (II) complex with the Josiphos bidentate phosphine for the particular case in which the N-nucleophile is ammonia. This reaction is one of the few examples in which ammonia can act as a reagent for the formation of a C-N bond. A mechanism of reaction has been proposed when the ligand attached to the metal center is bidentate. The behavior of ammonia in the reaction has been analyzed and the role played by a strong base in the mechanism of the reaction has been studied.
Kunchithapatham, Kamala. "Development of Calcium and Palladium Catalysts for the Formation of Carbon-Carbon and Carbon-Heteroatom Bonds." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337955731.
Full textRoşca, Sorin-Claudiu. "Alkaline-earth complexes supported by fluorinated ancillary ligands." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S155/document.
Full textThe catalysed additions of amines or phosphines across unsaturated substrates (alkenes, alkynes or allenes) constitute atom-efficient routes for the production of valuable fine chemicals such as amines and phosphines. For these reactions, heteroleptic alkaline-earth complexes have emerged as promising precatalysts. This PhD thesis describes the synthesis and characterisation of a series of alkaline-earth complexes of type [{RO}AeN(SiMe2H)2] supported by fluorinated aminoalkoxides ({RO} = fluorinated aminoalkoxide; Ae = Ca, Sr ). X-ray diffraction studies show that these complexes heavily involve Ae···F–C and β-Si–H···Ae secondary interactions to achieve kinetic stabilisation. Remarkably, these so-called secondary, non-covalent interactions can be more beneficial towards the stabilisation of the metallic species than the coordination of ethers onto the metal centre. Furthermore, fluorinated aminoalkoxo ligands were used to prepare rare examples of Ae heteroleptic complexes featuring intramolecular coordination from π donors (i.e. alkenes and alkynes). For the first time, Ae complexes stabilised by a combination of Ae···Cπ, Ae···F–C and β-Si–H···Ae interactions were described. The structural and electronic features of these unique complexes were probed by crystallographic, spectroscopic and computational (DFT) methods. The utilisation of aryl-containing ligands resulted in the formation of trinuclear complexes featuring a unique pattern of strong β-Si–H···Ca agostic interactions. Some of these calcium heteroleptic complexes were tested in the hydrophosphination of styrene and HPPh2. They displayed high activities (TOF ≈ 50 h–1) under mild conditions with 100% regioselectivity towards the anti-Markovnikov addition product. In a collaboration with Prof. M. Etienne and Dr. C. Dinoi from the Laboratoire de Chimie de Coordination (Toulouse), a heteroleptic calcium complex supported by a fluorinated tris(indazolyl)borate was used in the intramolecular hydroamination of 2,2-dimethylpent-4-en-1-amine, and it displayed excellent performances
Gregory, Alexander William. "Cyclisation cascades via reactive iminium intermediates." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:8e633fee-3457-4c31-939c-4421fac2fb8f.
Full textVuong, Khuong Quoc Chemistry Faculty of Science UNSW. "Metal complex catalysed C-X (X = S, O and N) bond formation." Awarded by:University of New South Wales. Chemistry, 2006. http://handle.unsw.edu.au/1959.4/23015.
Full textChilleck, Maren Annika. "Lewis-acide Zinkkomplexe." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17027.
Full textCationic zinc complexes are assumed to act as catalytically active species in various Lewis acid catalyzed reactions. However, the mechanisms of these reactions are poorly understood. The aim of this dissertation is to synthesize structurally well-defined cationic zinc organyls as model compounds for catalytically active species in zinc catalyzed reactions. The thesis focuses on zinc complexes bearing cyclopentadienyl (Cp) ligands, as Cp ligands can stabilize unusual bonding situations. The successful synthesis and characterization of several cationic zinc complexes with pentamethylcyclopentadienyl (Cp*) ligands is described. As a common structural feature of these complexes, the zinc center is coordinated by a Cp* ligand and additional neutral ligands. The highly electrophilic character of these compounds was proven in reactivity studies. A further approach to stabilize cationic zinc compounds is to apply functionalized Cp ligands featuring a donor group in a side chain. Neutral and cationic zinc complexes bearing amino- and thio-functionalized Cp ligands were synthesized and characterized. The cationic donor-functionalized complexes were shown to exhibit an intramolecular stabilization of the zinc atoms by the donor groups. Several zinc complexes which are described in this thesis were examined as precatalysts in intermolecular hydroamination reactions. In some cases high catalytic activities were achieved. Studies on the mechanism of the catalysis reactions revealed that the presence of a highly electrophilic zinc center is crucial for good catalytic performance.
Krüger, Karolin [Verfasser]. "Synthesis of biologically active N-heterocycles and amines via catalytic hydroamination of alkynes / von Karolin Krüger." 2008. http://d-nb.info/991583264/34.
Full textAljuhani, Maha A. "Towards Supported Nitrogen Containing Fragments on Silica Surface for Catalytic Applications." Diss., 2019. http://hdl.handle.net/10754/660092.
Full textHesp, Kevin. "Late Transition Metal Complexes for E-H Bond Activation and Additions to Multiple Bonds." 2010. http://hdl.handle.net/10222/13104.
Full textLee, seong du. "Gold(I)-Catalyzed Enantioselective Hydroamination of Unactivated Alkenes." Diss., 2012. http://hdl.handle.net/10161/6169.
Full textNumerous methodologies for efficient formation of carbon-nitrogen bonds have been developed over the decades due to the widespread importance of nitrogen containing compounds in pharmaceuticals and bulk commercial chemicals. Among many methods, hydroamination, especially, has attracted enormous attention because of its atom-economical characteristic to synthesize amine moieties. As a result, numerous publications have been reported relating the hydroamination reaction using various metal catalysts. However, the hydroamination of unactivated alkenes still remains a challenge task because of the low reactivity of the CC double bond. Recent development of superior gold(I) catalysis in many organic transformations stimulated us to develop efficient gold(I)-catalyzed methods for enantioselective intra- and intermolecular hydroamination of unactivated alkenes.
A gold(I)-catalyzed system for enantioselective intramolecular hydroamination of unactivated alkenes has been developed. For the effective gold(I)-catalyzed method, various gold(I)-catalysts have been synthesized and tested. Among the catalysts, bis(gold) complexes containing an axially chiral bis(phosphine) ligand catalyze the enantioselective intramolecular hydroamination of unactivated alkenes with carboxamide derivatives, most effectively. The method was effective for both carbamates and ureas to form pyrrolidine derivatives with up to 85 % ee.
The first enantioselective intermolecular hydroamination of unactivated alkenes was realized by a gold(I)-catalyzed method. The gold(I) catalyst system adds cyclic ureas to unactivated 1-alkenes to produce corresponding enantiomerically enriched hydroamination product in good yield with enantioselectivity up to 78 % ee.
Polymer-embedded ligands have been synthesized to demonstrate proofs of concepts for fluxional mechanocatalysis. We applied a certain shear stress using a rheometer in the course of palladium-catalyzed asymmetric allylic alkylation to examine catalytic reactivity change under the mechanical force.
Dissertation
Lefèvre, Xavier. "Complexes pinceurs de cobalt et de nickel : synthèse, caratérisation, réactivité." Thèse, 2010. http://hdl.handle.net/1866/5085.
Full textA large variety of new POCOP pincer type complexes of cobalt and nickel have been prepared. All those complexes are based on the following POCOP pincer type ligand: 2,6-(i-Pr2PO)2C6H4 In the case of cobalt, a new synthetic pathway has been developped. Unlike nickel, complexes containing cobalt in the +III oxidation state are obtained, the mechanism of their formation remains unknown. These complexes are paramagnetic. The dibromo derivative is light-sensitive, decomposing by losing a bromine to form the Co(II) pincer complex. The reactivity of those complexes has been studied. Concerning nickel, the catalyzed hydroamination has been extended to the derivates of acrylonitrile, crotonitrile and methacrylonitrile and to aromatic amines. Moreover, hydroaryloxylation reaction has been studied under the same conditions. Finally, amidines formation was obtained with 4-cyanostyrene and with cinnamonitrile. A pincer complex bearing this amidine moiety has been isolated. The cationic complex reacts with strong coordinating anions like cyanide and isocyanate. Moreover, the triflate anion is displaced by water, acrylonitrile and acrylonitrile derivates. Finally, a particular reactivity has been observed with morpholine, acetone and a 1:1 mixture of aniline and triethylamine.
Salah, Abderrahmen. "Complexes pinceurs de type POCOP de Nickel (II) : synthèse, caractérisation, réactivité et applications catalytiques." Thèse, 2011. http://hdl.handle.net/1866/6033.
Full textThis thesis describes the synthesis, spectroscopic characterization and the catalytic activities of a new family of pincer complexes of Ni (II) starting from the ligand POCOPPh (P,C,P-2,6-{Ph2PO}2C6H4) for which very few nickel complexes have been reported previsouly. We discuss the influence of P-substituents on the spectroscopic, electrochemical and catalytic activities of these complexes. The synthesis of POCOPPh has been improved comparatively to the procedure reported in the literature by reducing the reaction time to 30 minutes and the temperature to room temperature. The complex (P,C,P-2,6-{Ph2PO}2C6H3)NiBr was obtained with 88% yield by reacting the precursor NiBr2(NCCH3)x with POCOPPh . This complex was then reacted with various silver and potassium salts to give the following complexes (POCOPPh)NiCN, (POCOPPh)NiOTf, (POCOPPh)NiOAc and (POCOPPh)NiONO2 (OTf = triflate et OAc = acetate). The limited reactivity of the bromo derivative led us to use (POCOPPh)NiOTf for the preparation of some of the desired derivatives, such as (POCOPPh)NiCCPh. Attempts to prepare the desired alkyl derivatives (POCOPPh)NiR were not successful, but we were able to detect these derivatives using NMR. The thermal instability of (POCOPPh)NiR led to formation of new (POCOPPh)NiX complexes by halogen exchange with MgX2 or (POCOPPh)NiOH by hydrolysis. The cationic species [(POCOPPh)NiNCR][OTf] (R = Me, CHCH2, CHCHMe, C(Me)CH2, NCCH2CH2N(Ph)H) also were obtained easily from the (POCOPPh)NiOTf with good yields. All these complexes were characterized by elemental analysis, NMR spectroscopy (1H, 13C{1H} 31P{1H}, 19F{1H}), IR spectroscopy and UV-vis spectroscopy. For most complexes analysis by X-ray diffraction allowed us to establish their solid state structures. A few studies by cyclic voltammetry have been done to determine the electronic density of the metal center and the P-substituent influence on this characteristic. In order to investigate the effect of phosphine substituents on the catalytic activities of this type of complexes, catalytic studies were undertaken with the following two complexes (POCOPPh)NiOTf and (POCOPi-Pr)NiOTf in hydroamination of activated olefins specifically acrylonitrile. After optimization of experimental conditions, it was found that both complexes have similar activities but what makes a huge difference is the use of additives. Indeed, (POCOPi-Pr)NiOTf showed good catalytic activity in the presence of triethylamine as base but this activity decreased significantly in the presence of water. The opposite was observed with (POCOPPh)NiOTf complex: it was shown that triethylamine coordinates to the nickel center in this complex and hence reduces its activity in some cases. We Also explored other reactions such as the addition of the O-H bond in aromatic alcohols to acrylonitrile, and it was surprising that (POCOPPh)NiOTf is much more active than its homologous (POCOPi-Pr)-NiOTf. However aliphatic alcohols remain a major challenge for this kind of complex. Mechanistic studies suggest that this reaction passes through the following intermediates (POCOPPh)NiOAr and [(POCOPPh)NiOAr][HOAr]. These species were observed by NMR but not isolated.
Althammer, Andreas. "Entwicklung katalytischer Kreuzkupplungs- und Hydroaminierungsreaktionen." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-0006-ACB7-7.
Full text