Studying the synthesis and reactivity of sulfonium ylides derived via gold catalysts

• Main Author: Baker, Thomas
• Published: University of Birmingham 2014
• Subjects: 540; QD Chemistry
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619368

This thesis details the development of a gold-catalysed, ketone-stabilised ylide synthesis and the intermolecular reaction of this ylide. The reaction of this ylide with butenone proceeds via a novel, three-component coupling. This represents the first intermolecular reaction of a gold-derived ylide. The development of a novel, gold-catalysed, amide-stabilised ylide synthesis was also successful. The ylides underwent 2,3-sigmatropic rearrangements and Stevens 1,2-shifts. The Stevens rearrangement has previously not been reported for gold-derived ylides. These ylide transformations gave a range of novel, polysubstituted thiomorpholinones, which are difficult to access via classical approaches. The amide-stabilised ylides were found to be unsuitable for intermolecular reaction. Thioynol ethers were also investigated as triple-bonded substrates for gold-catalysed reactions. While the thioynol ethers were found to be significantly less reactive than the equivalent alkyne or ynamide, it was possible employ them for the synthesis of oxazoles in comparable yield to ynol ethers.