\(\pi\)-acid catalysed cyclisations to generate sulfur containing compounds

Kaur, Parmjit Heer (2014). \(\pi\)-acid catalysed cyclisations to generate sulfur containing compounds. University of Birmingham. Ph.D.

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Abstract

Complex scaffolds are readily accessed via Gold and Platinum π-acid catalysis starting from simple precursors. These precious metal π-acids are used to generate sulfur ylides which undergo rearrangement to interesting sulfur containing compounds analogous to those formed via diazo-chemistry. In this thesis the utility of these π-acids to generate sulfur ylides will be discussed by: 1) The in situ generation of α-carbonyl carbenoids directly from alkynes avoiding “sacrificial functionality”; 2) Achieving different regiochemical outcomes using electronically biased alkyne systems; 3) Designing domino reactivity using simple functional groups. Recent developments involve the use of ynamides as regio-directing agents for site specific oxygen-transfer from a suitable oxidant to form the α-oxo-gold-carbenoid functionality. These carbenoids mimic the reactivity observed by decomposition of diazo-compounds with non-precious transition metals. A new gold catalysed intramolecular rearrangement of ynamide tethered-sulfoxides have led to highly complex products. Designing the starting sulfoxide substrates to allow tandem cyclisation reactions have led to formation of polycyclic sulfur heterocycles which are close to sulfur analogues of known biologically active compounds.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):