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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Investigating rhodium-catalysed hydroacylation and carbon-carbon bond activation

Coxon, Thomas January 2017 (has links)
The work described in this thesis documents the development of new rhodium(I)-catalysed methodologies within two areas of research. The first examines the use of carbonyls as chelating groups in hydroacylation to produce synthetically valuable ketones and enones. The second area explores new carbon-carbon bond activation methodologies. Chapter 1 presents a literature review of the historical development of rhodium-catalysed hydroacylation, with a focus on chelating groups that can currently be used to suppress decarbonylation. A brief review of methodologies that avoid the requirement for a tether is also included. Chapter 2 describes the development of a novel hydroacylation methodology employing carbonyl-based functional groups as tethers on aldehyde substrates. The chapter begins with the optimisation studies for the hydroacylation of β-formyl amides with terminal and internal alkynes, allenes and terminal alkenes, and subsequently explores the substrate scope for each case. The chapter then outlines the investigations undertaken with 1,4-dicarbonyl and 1,5-dicarbonyl systems, N-formyl amides, β-formyl esters and finally β-formyl ketones. A detailed description of the routes undertaken to synthesise each starting material is also presented. Chapter 3 presents a short review surveying the key milestones in the development of carbon-carbon activation methodologies. The chapter begins with a theoretical comparison to carbon-hydrogen activation and a discussion of the unique challenges that are faced. An overview of the major strategies employed to enact these processes is subsequently presented for both strained and unstrained substrates. Chapter 4 outlines the attempts undertaken to develop a novel carbon-carbon bond activation methodology. The work evaluates sulfur-, nitrogen- and alkene-based chelating groups, known to be successful in hydroacylation, in analogous ketone substrates. Chapter 5 discusses the conclusions from this work and the potential for further work. Chapter 6 presents the experimental procedures and data.
2

The synthesis of the cyclometallated palladium complexes and their applications in olefin oligomerization and in phenylacetylene oligomerization/polymerization.

Mungwe, Nothando Wandile. January 2007 (has links)
<p><font face="TimesNewRomanPSMT"> <p align="left">This thesis reports the synthesis of the imine ligands from Schiff base condensation reaction of aldehyde derivatives and equimolar quantities of aniline derivatives. The imine ligands spectrometry.</p> </font></p>
3

The synthesis of the cyclometallated palladium complexes and their applications in olefin oligomerization and in phenylacetylene oligomerization/polymerization.

Mungwe, Nothando Wandile. January 2007 (has links)
<p><font face="TimesNewRomanPSMT"> <p align="left">This thesis reports the synthesis of the imine ligands from Schiff base condensation reaction of aldehyde derivatives and equimolar quantities of aniline derivatives. The imine ligands spectrometry.</p> </font></p>
4

The synthesis of the cyclometallated palladium complexes and their applications in olefin oligomerization and in phenylacetylene oligomerization/polymerization

Mungwe, Nothando Wandile January 2007 (has links)
Magister Scientiae - MSc / This thesis reports the synthesis of the imine ligands from Schiff base condensation reaction of aldehyde derivatives and equimolar quantities of aniline derivatives. The imine ligands spectrometry.
5

Carbon-Hydrogen and Carbon-Fluorine Bond Activation Promoted by Adjacent Metal Centres

Slaney, Michael E Unknown Date
No description available.
6

Studies on Asymmetric Hetero-Michael Addition Utilizing Various Modes of Organocatalytic Activation / 有機分子触媒による様々な活性化を利用した不斉ヘテロマイケル付加反応に関する研究

Fukata, Yukihiro 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19725号 / 工博第4180号 / 新制||工||1645(附属図書館) / 32761 / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 松原 誠二郎, 教授 中尾 佳亮, 教授 杉野目 道紀 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
7

Rh-catalyzed asymmetric C-H bond activation by chiral primary amine

Taleb Sereshki, Farzaneh 03 February 2017 (has links)
Developing asymmetric C-H bond activation methods in order to achieve enantiopure products is crucial for the advancement of the field and for the production of novel chiral compounds. Therefore, we tried to develop this area of organic chemistry by presenting metal catalyzed stereoselective C-H bond activation utilizing chelation-assisted tools. The first section of this study involves Rh(I) catalyzed asymmetric C-H bond activation of a series of ketones via an intermolecular procedure. By this method, we examine ortho-alkylation of aromatic ketones and β-functionalization of α-β unsaturated ketones with a series of prochiral olefins. In the second section, we present an efficient three steps method for stereoselective intramolecular C-H bond activation of indol-3-carboxaldehyde with tethered prochiral olefins. The catalytic system in both methods involves a joint chiral primary amine and Rh(I) catalyst. Chiral primary amines can serve to induce enantioselectivity as well as acting as a useful directing group which has shown appropriate coordination to the transition metal catalyst, providing high regioselectivity. / February 2017
8

Synthesis and Mechanistic Studies on the Reaction of N-phenylpyridin-2-Amine Palladacycle with Aryltrifluoroboratess to 9-(pryidin-2yl)-9H-carbazole

Li, Ya-Ming 09 August 2010 (has links)
An effiecient stoichiometric amount system has been developed for the synthesis of N-phenylpyridin-2-amine Palladacycle, and then reation with aryl trifluoroborate to 9-(pyridine-2-yl)-9H-carbazoles by C-H bond activation/ C-C bond formation and C-N bond formation. The subsitutent effect of the aryl trifluoroborate with N-phenylpyridin-2-amine Palladacycle intermediate was observed. Mechanistic studies of C-H bond cleavaged, including trapping of reaction intermediates and kinetic isotope effect experiments, are also presented.
9

Rhodium and Iridium Pincer Complexes Supported by Bis(phosphino)silyl Ligation: Applications in Bond Cleavage Chemistry

Morgan, Erin 22 May 2013 (has links)
Group 9 transition metal pincer complexes have shown tremendous utility in a variety of E-H (E = main group element) bond activation reactions. In an effort to access new types of highly reactive pincer-like transition metal complexes this research focuses on the development of new late metal complexes supported by tridentate bis(phosphino)silyl ligands of the type [?3-(2-R2PC6H4)2SiMe]- ([R-PSiP]; R = Cy, iPr). The incorporation of a strongly electron donating and highly trans-labilizing silyl group at the central anionic position may promote the formation of new coordinatively unsaturated compounds capable of enhanced reactivity. In this regard, the synthesis of coordinatively unsaturated Rh and Ir complexes supported by R-PSiP ligation and their ability to activate E-H bonds will be detailed. The synthesis of Cy-PSiP ligated Rh and Ir species and the ability to access the products of N–H bond oxidative addition with these species was investigated. Both [Cy-PSiP]Rh and [Cy-PSiP]Ir complexes were shown to form isolable complexes of the type [Cy-PSiP]M(H)(NHR) (M = Rh, R = aryl; M = Ir, R = H, aryl). However, attempts to generate such amido hydride complexes by N-H activation of the corresponding amine led to divergent reactivity, where adducts of the type [Cy-PSiP]Rh(NH2R) were obtained for Rh, while N-H bond oxidative addition was observed for Ir to form the targeted amido hydride complexes, including a rare example of ammonia N-H bond oxidative addition to form a monomeric, terminal parent amido complex that was crystallographically characterized. Due to the scarcity of transition metal complexes that are capable of N-H bond oxidative addition, a thorough investigation of the N-H bond activation mediated by [Cy-PSiP]Rh and Ir with various N-H containing substrates, including alkyl amines, hydrazine derivatives, and benzamides was initiated. Extension of this reactivity to the related diisopropylphosphino derivative [iPr-PSiP]IrI was also probed, as the resulting complexes were envisioned to be less susceptible to potential cyclometalation processes. Indeed, oxidative addition of primary alkyl amines, hydrazines, and benzamides was observed for [R-PSiP]Ir. These results comprise an unprecedented example of a metal complex that is capable of facile N-H bond activation in such a wide range of substrates, including challenging substrates such as ammonia and alkyl amines. A rare example of Rh-mediated N-H oxidative addition was also observed for the reaction of [Cy-PSiP]RhI with benzophenone hydrazone. The potential for these [R-PSiP]Ir(H)(NHR) complexes to insert unsaturated substrates was investigated, as the development of new pathways for the formation of C-N bonds via transition metal catalyzed N-H bond oxidative addition to a metal center followed by insertion of an alkene or alkyne into the M-N or M-H bond may provide a new pathway for accessing intermolecular amination reactions. Insertion chemistry attempts with various alkenes, alkynes, allenes, C=O and C?N containing compounds is described. Lastly, the synthesis of IrIII complexes of the type {[R-PSiP]IrR'}+X? (R = Cy, iPr; R’ = H, Me; X = OTf, BF4, B(C6F5)4) and their interactions with the C-H bonds of arenes and aldehydes, as well as, the Si-H bonds of hydrosilanes is detailed. The Si-H bond activation chemistry observed was typically influenced by the counter anion X. Thus, the more coordinating anions OTF and BF4 were shown to coordinate to and stabilize the highly electrophilic Si in transiently generated Ir silylene species.
10

Development of New Cobalt Pincer Complexes for Catalytic Reduction Reactions

Li, Yingze 18 October 2019 (has links)
No description available.

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