dc.contributor.advisor |
Wright, L |
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dc.contributor.author |
Hudson, Leroy |
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dc.date.accessioned |
2015-08-26T01:04:24Z |
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dc.date.issued |
2015 |
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dc.identifier.citation |
2015 |
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dc.identifier.uri |
http://hdl.handle.net/2292/26819 |
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dc.description |
Full text is available to authenticated members of The University of Auckland only. |
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dc.description.abstract |
Carbon-carbon (C-C) and carbon-nitrogen (C-N) coupling reactions are some of the most useful in synthetic chemistry as they allow the introduction of groups with useful functionality and facilitate further derivatisation of precursor molecules. Reactions of this type, such as the Heck, Suzuki and Buchwald-Hartwig reactions, are so versatile and are of such importance that, in the case of the Heck and Suzuki reactions, they resulted in the award of the 2010 Nobel Prize for Chemistry. The main objectives for this research were to study the use of two previously synthesised pre-catalysts but as yet, unreported pre-catalysts and to study the effectiveness of these in Heck and Suzuki C-C coupling reactions and Buchwald-Hartwig aminations. The possibility that palladium nanoparticles are the active species in these reactions was investigated and attempts were made to synthesise and characterise new pre-catalysts using different 2-aminopyridine-type materials. The two previously synthesised but unreported compounds that were used were [Pd6(HAMP)7(AMP)2](OAc) (HAMP = mono-deprotonated 2-amino-6-methylpyridine; AMP = doubly deprotonated 2-amino-6-methylpyridine) and [Pd5(HAP)7(AP)](OAc) (HAP = mono-deprotonated 2-aminopyridine; AP = doubly deprotonated 2-aminopyridine). These were used to catalyse Heck, Suzuki and Buchwald-Hartwig reactions under typical conditions. Results of the Heck reaction (which involved the reaction between bromobenzene and styrene to form stilbene) show great promise for these catalysts as almost complete conversion can be achieved at a concentration as low as 0.005 mol% Pd with about 90% selectivity for the trans- or E- isomer. Other aryl halides were also screened in the Heck reaction. Evidence was obtained that in the Heck reactions the palladium compounds decomposed to give highly active palladium nanoparticles and it was these that were the active catalytic species. Scanning and transmission electron microscopy (SEM and TEM respectively) and energy dispersive spectroscopy (EDS), were techniques used to examine this possibility where particles rich in palladium with an average size range of 20.0-30.0 ± 0.3 nm in diameter were observed. Heterogeneity tests such as light scattering, Hg drop and use of an authentic heterogeneous Pd catalyst were performed to confirm the Pd nanoparticles are the active species in the reactions studied. |
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dc.publisher |
ResearchSpace@Auckland |
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dc.relation.ispartof |
Masters Thesis - University of Auckland |
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dc.relation.isreferencedby |
UoA99264820511802091 |
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dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
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dc.rights |
Restricted Item. Available to authenticated members of The University of Auckland. |
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dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
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dc.rights.uri |
http://creativecommons.org/licenses/by-nc-nd/3.0/nz/ |
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dc.title |
Development of palladium complexes with simple 2-aminopyridine-type ligands as pre-catalysts for carbon-carbon coupling reactions |
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dc.type |
Thesis |
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thesis.degree.discipline |
Chemistry |
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thesis.degree.grantor |
The University of Auckland |
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thesis.degree.level |
Masters |
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dc.rights.holder |
Copyright: The Author |
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pubs.elements-id |
495480 |
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pubs.record-created-at-source-date |
2015-08-26 |
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dc.identifier.wikidata |
Q112909258 |
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