This thesis describes the use of both sulfuric acid and triflic acid, to promote hydroamination and hydroalkoxylation cyclisations for the formation of N- and Oheterocycles. Chapter 2 describes the synthesis of 2,2,6-trisubstetuted piperidine. A wide range of protecting groups has been employed in the cyclisation. A new, general and flexible method for the highly enantioselective synthesis of chiral piperidine and spiropiperidine has been developed. The main advantages of this synthetic method lie in the readily availability of the precursors. There is no reason why this reaction cannot find further application in natural product synthesis. Chapter 3 describes a miscellany of cascade and transannular cyclizations. The hydroamination has also been used to form the sterically crowded bridged isoquinuclidines through a transannular cyclisation, which would have rearranged to the less hindered products. We have also applied acid-catalyzed intramolecular cascade methodology to the synthesis of polycyclic hydroquinolines. Oxygen-centered transannular cyclisation has been compared with nitrogen-based examples, by acid-catalyzed hydroalkoxylation cyclisation to give only the sterically crowded bridged cineoles. Chapter 4 describes a new discovery of a novel N-to-O transfer reaction.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:646312 |
| Date | January 2014 |
| Creators | Aldmairi, Abdul Hadi |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/73199/ |
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