This thesis presents the application and development of H-bond donor organocatalysts. Chapter 2 presents an intramolecular Michael addition of β-dicarbonyls onto α,β-unsaturated esters catalyzed by tertiary amine/H-bond donor bifunctional catalysts, achieving up to 88% ee. Chapter 3 outlines the design and synthesis of a new family of cinchona-derived H-bond donor/ammonium salt phase-transfer catalysts. The ability of these asymmetric phase-transfer catalysts to activate less reactive substrates than their tertiary amine analogues and to induce higher levels of enantiocontrol than commercially available phase-transfer catalysts was demonstrated in an intramolecular Michael addition. Chapter 4 details the highly successful application of these new H-bond donor/ammonium salt phase-transfer catalysts to the enantio- and diastereoselective nitro-Mannich reaction of α-amido sulfones with nitroalkanes. Preliminary investigations into a novel phase-transfer catalyzed asymmetric ketimine reduction demonstrate the ability of these catalysts to provide access to new methods.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:711776 |
| Date | January 2014 |
| Creators | Johnson, Kayli Marie |
| Contributors | Dixon, Darren J. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:203f5242-552c-43de-9796-cd3693611156 |
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