Making and breaking carbon–carbon bonds at main group metal hydrides
File(s)
Author(s)
Parr, Joseph Michael
Type
Thesis
Abstract
This thesis centres around the idea of making (Chapters 1-3) and breaking (Chapters 4-6) carbon–carbon (C–C) bonds. Chapter 7 describes efforts toward fluorine shuttling at a bimetallic centre, work carried out during my time as a JSPS Fellow at Kyoto University. In Chapter 8 the combined experimental data from Chapters 1-6 are listed.
In Chapters 1-3 we focus on the idea of generating C–C bonds from syngas, mixtures of carbon monoxide (CO) and dihydrogen (H2). Such reactions underpin the industrially relevant Fischer-Tropsch process. In Chapter 1, metal-formyl complexes are introduced and their role in C–C bond formation reviewed. In Chapter 2, the reaction of a soluble magnesium hydride complex with a series of transition metal carbonyl complexes are documented. In all cases, metal formyl complexes were isolated and crystallographically characterised. In Chapter 3, reaction of the isostructural calcium hydride with a series of carbonyl complexes (Co, Rh, Ir) were investigated. In all cases, mixtures of mono- and bis(formyl) complexes were generated and examples crystallographically characterised. DFT calculations were performed to understand the electronic influence of a second formyl ligand at a metal centre. At the end of Chapter 3, conclusions and future work from Chapters 1-3 are discussed.
In Chapters 4-6 our attention turned to reactions that break C–C bonds. In Chapter 4, emerging examples of C–C bond activation at main-group metals are reviewed. In Chapter 5, reaction of isostructural Mg and Zn hydride complexes with a series of methylidene cycloalkanes (C3 to C6 rings) is documented. C–C bond functionalisation via Mg catalysed hydrosilylation and hydroboration is then reported. In Chapter 6, DFT calculations are used to understand the reactivity differences between the Mg and Zn complexes. At the end of Chapter 6, conclusions and future work from Chapters 4-6 are discussed.
In Chapters 1-3 we focus on the idea of generating C–C bonds from syngas, mixtures of carbon monoxide (CO) and dihydrogen (H2). Such reactions underpin the industrially relevant Fischer-Tropsch process. In Chapter 1, metal-formyl complexes are introduced and their role in C–C bond formation reviewed. In Chapter 2, the reaction of a soluble magnesium hydride complex with a series of transition metal carbonyl complexes are documented. In all cases, metal formyl complexes were isolated and crystallographically characterised. In Chapter 3, reaction of the isostructural calcium hydride with a series of carbonyl complexes (Co, Rh, Ir) were investigated. In all cases, mixtures of mono- and bis(formyl) complexes were generated and examples crystallographically characterised. DFT calculations were performed to understand the electronic influence of a second formyl ligand at a metal centre. At the end of Chapter 3, conclusions and future work from Chapters 1-3 are discussed.
In Chapters 4-6 our attention turned to reactions that break C–C bonds. In Chapter 4, emerging examples of C–C bond activation at main-group metals are reviewed. In Chapter 5, reaction of isostructural Mg and Zn hydride complexes with a series of methylidene cycloalkanes (C3 to C6 rings) is documented. C–C bond functionalisation via Mg catalysed hydrosilylation and hydroboration is then reported. In Chapter 6, DFT calculations are used to understand the reactivity differences between the Mg and Zn complexes. At the end of Chapter 6, conclusions and future work from Chapters 4-6 are discussed.
Version
Open Access
Date Issued
2024-01-17
Date Awarded
2024-04-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Crimmin, Mark
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)