Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.733664
Title: The preparation and reactivity of a fluoroiodane reagent derived from fluoride
Author: Geary, Gemma Clare
ISNI:       0000 0004 6494 4705
Awarding Body: University of Leicester
Current Institution: University of Leicester
Date of Award: 2016
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Abstract:
The fluoraza reagents are selective, shelf stable and easy to handle sources of electrophilic fluorine but their applications are limited because they are normally made from elemental fluorine making them very expensive. In Chapter 2, the synthesis of a new electrophilic fluorinating reagent derived from cheap and readily available sources of the fluoride anion is described. The air and moisture stable fluoroiodane was prepared on a 6–10 g scale using TREAT-HF with no complicated purifications and without the need for dry or inert conditions. The fluoroiodane could also be prepared using TBAF, which is a commonly used source of fluoride for the production of [18F]-labelled radiotracers for positron emission tomography (PET). Preliminary reactivity studies showed that the fluoroiodane could be used to fluorinate 1,3-ketoesters and 1,3-diketones in good yields (45–88%). It was subsequently found in Chapter 3 that, in these reactions, the fluoroiodane simulated an electrophilic fluorination via an addition-substitution mechanism. In Chapter 4, the fluoroiodane was also used for the intramolecular fluorocyclisation of unsaturated carboxylic acids to prepare novel fluorinated γ-lactones under mild conditions in the presence of AgBF4. This reaction combined a cyclization, an aryl migration and a fluorination to deliver lactones which contain a tertiary alkyl fluoride. The fluoroiodane could also be used without a metal catalyst to give moderate yields in just 1 h demonstrating that it is a suitable reagent for developing new 18F-labelled radiotracers for PET imaging. Finally, the synthesis of an acid derived fluoroiodoxolone species was attempted in Chapter 5. Unfortunately, however, the fluoroiodoxolone was difficult to prepare, insoluble, and unstable. It was also found that the fluoroiodoxolone was considerably less reactive than the fluoroiodane in the fluorination of 1,3-dicarbonyl compounds.
Supervisor: Stuart, Alison ; Hope, Eric Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.733664  DOI: Not available
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