Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313445
Title: Asymmetric synthesis : approaches via enantiomerically pure acetal and oxazoline ligands
Author: Newman, Louise M.
Awarding Body: Loughborough University
Current Institution: Loughborough University
Date of Award: 1999
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Abstract:
This thesis describes the synthesis of novel ligands that include enantiomerically pure acetal and oxazoline moieties. These ligands are utilised in a number of metalmediated asymmetric syntheses. All asymmetric acetals and pyridine based acetals are synthesised in good yield in a single step from their corresponding enantiomerically pure diols. C2 symmetric bisacetals are investigated as ligands in the organolithium and Grignard additions to benzaldehyde with promising results. C2 symmetric bisacetals and pyridine based acetals are tested for their ability to induce asymmetry in copper(l) catalysed cyclopropanation of styrene using ethyl diazoacetate and the lanthanide(lII) catalysed Diels-Alder cycloaddition involving Danishefsky's diene with little success. Enantiomerically pure phosphinooxazoline ligands are available in good yield in two steps from their corresponding enantiomerically pure aminoalcohols. Enantiomerically pure acetal substituted pyridines and phosphinooxazoline ligands are considered in the rhodium (I) catalysed hydrosilylation of ketones. Reaction conditions for the more successful phosphinooxazoline ligands are optimised. Using these ligands a range of enantiomerically enriched alcohols is presented in good yield and enantiomeric excess. Novel phosphinooxazoline ligands are applied to the palladium(O) catalysed allylic substitution reaction with excellent enantioselectivities of the substitution product.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.313445  DOI: Not available
Keywords: Acetal ; Acetalisation ; Asymmetric ; Catalysis ; Cyclopropanation ; Diels-Alder ; Diol ; Enantiomeric excess ; Grignard ; Hydrosilyation ; Ligand ; Oxazoline ; Palladium allylic substitution ; 1-phenylethanol ; Rhodium Chemistry, Organic
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