Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 8 of 8 for “"Chiral cations"”.
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New Catalysts for Asymmetric Nitrene Transfer Based on Ion-Pairing Between Sulfonated Rhodium(II,II) Tetracarboxylates and Chiral Cations: Design, Synthesis and Applications to Enantioselective Carbon-Nitrogen Bond Formation
… Sulfonated Rhodium(II,II) Tetracarboxylates and Chiral Cations: Design, Synthesis and Applications to Enantioselective Carbon-Nitrogen Bond Formation – Alexander Fanourakis The work presented in this thesis investigates a new strategy for the catalytic, asymmetric synthesis of C(sp3)–N bonds and …
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The Design and Application of Ion-paired Ligands to Address Selectivity Challenges in Transition Metal Catalysed Oxygen and Nitrogen Transfer Reactions
… approaches in this field involve the use of chiral ligands on the metal to induce asymmetry and whilst a well-proven approach to enantiocontrol, it is not universally applicable. Our group has developed an alternative approach in which achiral anionic ligands are ion-paired to chiral cations …
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The Application and Evolution of Chiral Ion-Paired Rhodium(II,II) Tetracarboxylate Catalysts for Enantioselective Nitrene Transfer
… nitrene transfer chemistry employing chiral ion-paired dirhodium catalysts. The initial development of this catalyst family was reported previously by the Phipps group and their design is based on a strategy for the combination of transition metal complexes and cinchona …
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Investigations of Catalysts Which Utilise Non-Covalent Interactions to Control Enantioselectivity in Rhodium-Catalysed Amination of C(sp3)–H Bonds
… bond between the substrate-based carbonyl and chiral cation-based hydroxyl, with ancillary binding also shown to be viable. Additionally, the key role of a hypervalent iodine additive was uncovered. Overall, this thesis seeks to expand the utility of ion-paired chiral cations for …
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Controlling the Regio- and Enantioselectivity of Iridium-Catalysed Arene Borylation Using Sulfonated Bipyridine Ligands
… moderate. Despite their often-privileged nature, chiral cations have generally found limited use in transition metal catalysis. The second part of this thesis explores a strategy in which a chiral cation, derived from the privileged class of cinchona alkaloids, is associated with an anionic …
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The Development of Enantioselective Rhodium-Catalysed Aziridination Reactions Directed by a Chiral Cation
Aziridines are versatile precursors to prepare chiral nitrogen-containing compounds. Whilst great advances have been developed in asymmetric intermolecular aziridination, there remain significant gaps in the scope of alkenes that can be accommodated with present protocols. Chapter 2 discusses the …
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Development of Ion Pairing Strategies that Utilise Cations to Control Selectivity in Transition Metal-Catalysed Functionalisation of C–H Bonds
… strategies explored in this thesis focus on how cations may be used to influence such reactivity at their closely associated anions. Chapter 2 focusses on the iridium-catalysed borylation of aromatic C(sp2)–H bonds. The lack of regiocontrol for 1,2-disubstituted arenes under standard conditions …
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Control of chiral optical and spin properties in low-dimensional perovskites
… geometric tolerance factors to small monovalent cations and a limited set of simple organic molecules, 2D perovskites can accommodate large organic spacer cations between inorganic layers, enabling diverse organic cations incorporation. This expanded molecular design allows the introduction of …