Lewis acid-promoted (3+2) cycloadditions and multi-component reactions of methyleneaziridines
Griffin, Karen, PhD (2011) Lewis acid-promoted (3+2) cycloadditions and multi-component reactions of methyleneaziridines. PhD thesis, University of Warwick.
WRAP_THESIS_Griffin_2011.pdf - Submitted Version - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Official URL: http://webcat.warwick.ac.uk/record=b2561010~S1
This thesis describes our attempts towards realising new chemistry involving methyleneaziridines, for the main part, focusing on novel cycloaddition reactions involving this unique, densely functionalised heterocycle. Contrary to methyleneaziridines, the cycloaddition reactions of aziridines have been extensively studied. Thus, chapter one presents an introduction and literature review of cycloaddition reactions involving the aziridine nucleus, in order to contextualise the research described in chapter two. Chapter two describes the discovery and development of a novel Lewis acidpromoted (3+2) cycloaddition reaction of methyleneaziridines onto alkyne and alkene acceptors. Both inter- and intramolecular variants of this methodology were examined. The latter substrates being readily made by functionalisation of the parent methyleneaziridines through an efficient lithiation/alkylation sequence. These cycloadditions most likely proceed in a stepwise manner through opening of the methyleneaziridine by the nucleophilic alkene (or alkyne) and subsequent ring closure of the nitrogen atom onto the resultant carbocation. This chemistry provides a powerful new approach to a variety of heterocyclic systems including highly functionalised pyrroles and pyrrolidines. Chapter three begins with a brief introduction to multicomponent reactions, focusing on those which incorporate the methyleneaziridine nucleus. Our efforts towards realising new multicomponent reactions involving methyleneaziridines are detailed. Specifically, the attempted syntheses of 3,4-dihydro-1(2H)-isoquinolones, α-fluorinated and N-t-butylsulfinyl ketimines are described. Chapter four details the experimental procedure and characterisation data for the novel compounds produced in this thesis.
|Item Type:||Thesis or Dissertation (PhD)|
|Subjects:||Q Science > QD Chemistry|
|Library of Congress Subject Headings (LCSH):||Ring formation (Chemistry), Heterocyclic compounds|
|Institution:||University of Warwick|
|Theses Department:||Department of Chemistry|
|Sponsors:||Engineering and Physical Sciences Research Council (EPSRC)|
|Extent:||238 leaves : ill., charts|
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