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Title: Studies on carbon-carbon bond formation : copper mediated oxidative coupling of alkenyl silanes and efforts towards a direct catalytic enolate SN2 alkylation reaction
Author: Blackwell, D. T.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2010
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Abstract:
This thesis describes two research projects aimed at the design and development of new methods for the construction of carbon-carbon bonds. The first focused on attempts to extend previous work within the Spring Group on the formation of biaryl-containing medium rings via the oxidative coupling of organocuprates to the formation of dienyl and alkenyl medium rings. It was found that functionalised alkenylsilanes bearing a pendant coordinating group could be prepared with good control over the geometry of the alkene, and undergo stereospecific fluoride-mediated transmetalation to copper followed by thermolytic or oxidative dimerisation of the so-formed alkenylcopper species to yield symmetrical dienes. Unfortunately, despite considerable effort, it was not possible to extend this finding to an intramolecular medium ring-forming variant of this reaction. The goal of the second project was to develop a novel catalytic soft enolisation – SN2 alkylation reaction carbonyl compounds. Preliminary screens of various established Lewis acids, bases, and ligands did not provide any useful hits, and so a computational study was undertaken to develop a better understanding of the desired reaction and to identify means by which it might be promoted. This study suggested that a bifunctional Lewis acid catalyst bearing a pendant quaternary ammonium ion might offer a solution to the problem at hand, and so a small library of such ligands was synthesised. A computational study of the proposed reaction identified two key flaws in the original reaction and ligand design and led to the design of a new ligand.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.596704  DOI: Not available
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