This thesis concerns the development of the first BINOL phosphoric acid (BPA) catalysed enantioselective N-acyliminium cyclisation reactions and their incorporation into domino sequences that allow for the construction of architecturally complex enantioenriched polycycles in a single step from easily accessible starting materials. More specifically, this thesis deals with the discovery of a BPA-catalysed enantioselective N-acyliminium cyclisation cascade of enol lactones and tryptamines. Its extension to a doubly catalysed process involving gold(I) to cycloisomerise alkynoic acids and a BPA to effect the enantioselective N-acyliminium cyclisation is presented. In addition, the exploitation of this method in highly diastereo- and enantioselective N-acyliminium cyclisations of oxoacids and tryptamines and in a site isolated base-catalysed Michael addition / acid-catalysed N-acyliminium cyclisation cascade is described. A study on the proposed mechanism and model for the origin of enantioselectivity is discussed, based on experimental data and a computational study. As a separate part of our programme, the development of a new class of stronger Brønsted acids, chiral benzenesulphonic acids, is described. The optimisation of the synthetic routes as well as the synthesis of a library of acids is presented and their assessment in precedented reactions is discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:580862 |
| Date | January 2010 |
| Creators | Muratore, Michael Eric |
| Contributors | Dixon, Darren J. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:07a40a20-b71f-47f4-b549-bf9d7ca27043 |
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