Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558388
Title: Transition metal catalysis in the presence of fluorinating reagents
Author: Hopkinson, Matthew Neil
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2011
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Abstract:
In this thesis, the effect of fluorinating reagents on a selection of transition metal-mediated organic transformations was investigated. The first four chapters are focused on gold-catalysed nucleophilic addition processes performed in the presence of “F⁺” sources. Chapter 1 provides a general introduction to homogeneous gold catalysis and summarises the aims and objectives of the project. The effect of the electrophilic fluorinating reagent Selectfluor (82) on the gold-catalysed rearrangement of propargyl acetates 85 is discussed in Chapter 2. α-Fluoroenones 92 resulting from fluorodeacetylation of an allenyl acetate intermediate were delivered as the major products of these reactions (Scheme i). [Scheme i Gold-Catalysed Rearrangement-Fluorodeacetylation of Propargyl Acetates 85.] By contrast, performing the gold(I)-catalysed cyclisation of allenoates 102 in the presence of Selectfluor (82) led to products of oxidative coupling. The “F⁺” source in these processes most likely acts as an external oxidant in an AuIIII redox cycle. In Chapter 3, the cascade cyclisation-intramolecular arylation of benzyl-substituted substrates is discussed whilst the extension of the methodology towards intermolecular homocoupling and intermolecular alkynylation is presented in Chapter 4 (Scheme ii). [Scheme ii Gold-Catalysed Cyclisation-Oxidative Coupling of tert-Butyl Allenoates 102.] In Chapter 5, the feasibility of palladium-catalysed allylic [18F]radiofluorination was investigated using high-specific-activity [18F]fluoride. This study led to the development of the first transition metal-mediated C-18F bond-forming process of relevance for the preparation of radiotracers for PET imaging (Scheme iii). [Scheme iii Palladium-Catalysed Allylic [18F]Radiofluorination of Allylic Methyl Carbonate 227b.] Chapter 6 gives full experimental procedures and characterisation data for all compounds.
Supervisor: Gouverneur, Véronique Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.558388  DOI: Not available
Keywords: Organic chemistry ; Organic synthesis ; Organometallic Chemistry ; homogeneous catalysis ; gold ; fluorine ; oxidative coupling ; radiochemistry
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