Triaryl oxonium ions: synthesis, reactivity and application as precursors to heterocyclic arynes

Thesis

The work described in this thesis explores the synthesis of heterocyclic triaryl oxonium ions and their application in hetaryne chemistry. It consists of four projects divided into concise chapters, each with a separate introduction, results and discussion, synthesis of starting materials, conclusion and future work sections.

Chapter 1 summarises the work on 2-quinolone and 2-pyridone oxonium ions, including the development of their synthetic routes and application in hetaryne trapping reactions, as well as a discussion of the observed regioselectivity.

In Chapter 2, the in situ generation and furan trapping of a 4-quinolone oxonium ion is reported as well as the strategies explored to increase its kinetic stability. A chromone oxonium ion is also produced and its reactivity compared to its isoelectronic counterpart.

Chapter 3 illustrates the structural design and synthesis of quinoline oxonium ions, establishing the necessity of an electron withdrawing group in the 2- position. Furthermore, a route to isoquinoline oxonium ion precursors is also developed.

Finally, Chapter 4 discloses the synthesis of benzothiophene, benzofuran and indolebased oxonium ions and the efforts to access their corresponding hetarynes.

Authors: Alisauskas, E

• DOI: 10.5287/ora-rdm2opxjd
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English