Thesis-2004-Thomas.pdf (4.44 MB)
Download fileApplication of N-acyliminium ions in the asymmetric synthesis of indole alkaloids
thesis
posted on 2018-09-21, 08:19 authored by Christopher I. ThomasWe have developed a new and highly stereoselective approach to indolizino[8,7-b]indole derivatives such as (A) and indolizino[2,3-a]quinolizidines (B). Our protocol
involves the cyclisation of pendent aromatic substituents onto N-acyliminium
intermediates as a key ring-forming step. The indolizino[2,3-a]quinolizidines are of
great interest and significance since this heterocyclic template is found within a
plethora of indole alkaloids.
[Illustration omitted.]
In order to demonstrate the synthetic potential of this methodology we have
established conditions for removal of the pendent hydroxymethyl substituent from
cyclisation products such as (A) and (B). Furthermore, we have demonstrated the
functionalisation of our cyclisation products via conjugate addition chemistry.
We have utilised this methodology and herein describe the asymmetric synthesis of
both enantiomers of deplancheine (C), furnishing the natural product and its
enantiomer with >95% e.e. Our route relies on a highly stereoselective cyclisation
reaction to access the indolizino[2,3-a]quinolizidine template from a readily available
non-racemic chiral template.
[Illustration omitted.]
History
School
- Science
Department
- Chemistry
Publisher
© Christopher Ian ThomasPublisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2004Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy at Loughborough University.Language
- en