Novel phosphonium salts and bifunctional organocatalysts in asymmetric synthesis

Moore, Graham (2013) Novel phosphonium salts and bifunctional organocatalysts in asymmetric synthesis. PhD thesis, University of Nottingham.

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Abstract

This thesis details the syntheses of catalysts and their applications in asymmetric reactions. Initially, the project focused on phase transfer catalysts; quaternary phosphonium salts derived from diethyl tartrate or from commercially available phosphorus compounds and their use primarily in the alkylation of N,N-diphenyl methylene glycine tert-butyl ester. Although some of the salts showed the ability to catalyse the alkylation reaction, all products obtained were racemic. The project then focused on bifunctional organocatalysis; catalysts derived from isoquinoline and BINOL were studied in Michael addition reactions between ethyl nitropropionate and MVK. Possible evidence for a bifunctional effect was observed, however, all Michael addition products obtained were racemic. Finally, an examination of proline-derived diamines as catalysts for aldol reactions is reported. Reversing the positions of the acid and base moieties of the catalyst results in the formation of the opposite enantiomer of the aldol product. In addition, these proline-derived diamines, along with two catalysts derived from a biarylazepine, were tested in a series of asymmetric reactions, with the best enantioselectivities (up to 90% ee) obtained in the conjugate addition between enones and nitro-containing compounds.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Lygo, B.
Woodward, S.
Subjects: Q Science > QD Chemistry > QD241 Organic chemistry
Faculties/Schools: UK Campuses > Faculty of Science > School of Chemistry
Item ID: 13366
Depositing User: EP, Services
Date Deposited: 31 Oct 2013 12:26
Last Modified: 27 Sep 2016 16:28
URI: http://eprints.nottingham.ac.uk/id/eprint/13366

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