Studies in asymmetric catalysis
Soni, Rina (2011) Studies in asymmetric catalysis. PhD thesis, University of Warwick.
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Derivatives of enantiomerically pure 1,2-cyclohexanediamine and 1,2-
diphenylethanediamine have been synthesised and used as organocatalysts for
asymmetric reactions. The derivatives of 1,2-diphenylethanediamine have been
employed for C-C, C-N bond formation reactions to determine their efficacy and
selectivity. Compound 278 has shown high efficiency and selectivity for addition of
aldehydes to DEAD.
Novel Ru-metal complexes containing enantiomerically pure N,N-dialkylated-1,2-
diamine ligands have been synthesised. Complexes 299 and 302 were used to study
asymmetric transfer hydrogenation of ketones and imines. These complexes were
found to be selective for the imine reduction compared to ketones reductions under
the conditions used. Results obtained by these complexes also provided support for
the proposal that reduction of the ketones involves a cyclic concerted mechanism for
the transfer of hydrogen, while reduction of imines involves transfer of hydride from
the complex through an ‘open’ transition state.
Asymmetric transfer hydrogenations of α,α-disubstituted ketones were carried out
using Ru-3C-tethered catalyst 181. Results obtained for asymmetric transfer
hydrogenation of these compounds show that unsaturation or an aromatic group in
substitution at the α-position of the ketone gave products of high enantioselectivity.
This may be due to the interaction between η6-arene ring of Ru-complex and the
group placed on the α-position of the ketone.
|Item Type:||Thesis or Dissertation (PhD)|
|Subjects:||Q Science > QD Chemistry|
|Library of Congress Subject Headings (LCSH):||Catalysts, Asymmetric synthesis|
|Official Date:||September 2011|
|Institution:||University of Warwick|
|Theses Department:||Department of Chemistry|
|Sponsors:||University of Warwick|
|Extent:||ix, 288 leaves : ill., charts|
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