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# Exploring regiocontrolled gold-catalysed alkyne activation for efficient synthesis of nitogen heterocycles

Chatzopoulou, Elli (2015)
Ph.D. thesis, University of Birmingham.

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## Abstract

In this thesis the development of regiocontrolled gold-catalysed reactions for the synthesis of complex heterocycles are described.

A new methodology for the formation of all-carbon fully substituted oxazoles was designed and developed, through a novel gold-catalysed intermolecular formal [3+2]-cycloaddition across the π-system of electron-rich internal alkynes by employing conjugated $$N$$-ylides as $$N$$-nucleophilic 1,3-$$N$$,$$O$$-dipole equivalents. This intermolecular addition to unsymmetrical internal alkynes represents a considerable regioselectivity and reactivity challenge, as there are no examples of intermolecular atom-transfer nitrene addition.

A new design of substrates incorporating an electron-rich π-system and a tethered oxidant or a nitrene delivery system was investigated. Several strategies towards the formation of these systems were proposed and the exhibiting limitations were identified.

A novel gold-catalysed reaction has been developed for the formation of complex polycyclic systems, which involves a [1,5]-hydride transfer/cyclisation cascade of functionalised aromatic and aliphatic ynamides. Under mild conditions, the process rapidly generates three fused ring systems by the formation of three new C(sp$$^3$$)-C(sp$$^3$$) bonds and up to four contiguous stereogenic centres, in a single manipulation.

Type of Work: Ph.D. thesis. Davies, Paul Colleges (2008 onwards) > College of Engineering & Physical Sciences School of Chemistry QD Chemistry University of Birmingham 6110
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