New catalytic strategies for chemical synthesis : (1) anti-aldol reactions from alkynes and (2) oxidative palladium (II) chemistry

This thesis reports the development of two new concepts for stereoselective catalysis and their application in organic synthesis. Chapter 1 and 2 highlight the importance of stereoselective aldol reactions and the current limitations for the generation of (E)-enolates of amides. An alternative strategy for the generation of (E)-enol silanes II was proposed starting from alkynes I, and concept was successfully extended to an anti-selective aldol reaction (Scheme I). The scope of this novel process is detailed in chapter 3 and studies toward an asymmetric variant, including mechanistic discussions, are also described. Chapter 4 highlights the current state of the art in enantioselective catalytic olefin functionalisation reactions, particularly focusing on strategies using palladium. The potential challenges that lead to the lack of asymmetric palladium(II) chemistry developed are also outlined, and our solution of using a 14 electron palladium/ligand complex to explore this area of chemistry is discussed . In chapter 5, the design and syntheses of chiral ligands are detailed. Applications of the catalyst are investigated in chapters 6, ee’s up to 84% has been achieved for the Wacker-type cyclisation. Finally, tuning of the ligands is demonstrated in chapter 7.EThOS - Electronic Theses Online ServiceGBUnited Kingdo