Transition metal catalysed cycloisomerisation of ene-ynamides

Obumselu, Onyeka Fabian (2019). Transition metal catalysed cycloisomerisation of ene-ynamides. University of Birmingham. Ph.D.

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Abstract

This thesis highlights the use of transition metal catalysts in the synthesis of highly functionalised nitrogen heterocycles using ene-ynamides as starting materials.
Relying on the initial discovery of copper-catalysed cascade reaction, a one pot carbon nitrogen bond formation and rearrangement cascade sequence has been developed to synthesise functionalised oxyisoquinolines with the use of an environmentally benign, inexpensive copper catalyst. The reaction proceeds through ynamide formation, followed by an initial aza-Claisen rearrangement, subsequent [1,5]-hydride transfer and 6π electrocyclisation. Exploration of the substrate scope and its limitations have allowed increased access to novel functionalised fused pyridine derivatives.
Finally, generation of five membered nitrogen based heterocycles with dienamide moieties through gold catalysed cycloisomerisation of 1,6-ene-ynamides is described. Polycyclisation of ynamides was also achieved through gold catalysis to afford tetracyclic products.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):