C–F bond functionalisation using main group reagents
File(s)
Author(s)
Coates, Gregory
Type
Thesis
Abstract
Fluorinated compounds have greatly increased our quality of life. They have found application in nearly every industry. Among their many uses they find applications as aerosols, in polymeric materials, as solvents and surfactants whilst they are particularly relied upon for refrigeration purposes. However, the fluorine industry is not currently sustainable. Most organofluorine compounds can be considered ‘single-use’ and the majority are lost into the atmosphere as fluorinated gases such as hydrofluorocarbons.
The desirable characteristics of organofluorine compounds are also their detriment. They are particularly inert to decomposition and are therefore persistent in the environment. The emission of fluorocarbons into the atmosphere is a significant contributor to climate change and environmental pollution. The recycling of fluorinated compounds therefore represents a timely challenge to synthetic chemists. Due to the increasing incorporation of fluorine into complex molecules such as pharmaceuticals and agrochemicals, the upgrading of fluorine-dense hydrofluorocarbons and hydrofluoroolefins (HFOs and HFCs) to fluorine containing reactive building blocks is an attractive method to close the fluorine cycle.
In this context, we demonstrate methods to selectively activate sp2 and sp3C–F bonds in fluorocarbons using main group compounds. We have developed efficient methods to chemically upgrade industrially relevant HFOs and HFCs to simple-bench stable silicon compounds. Furthermore, we have advanced the understanding of how to activate strong C–F bonds, by interrogating the reaction mechanisms using computational calculations (DFT).
The desirable characteristics of organofluorine compounds are also their detriment. They are particularly inert to decomposition and are therefore persistent in the environment. The emission of fluorocarbons into the atmosphere is a significant contributor to climate change and environmental pollution. The recycling of fluorinated compounds therefore represents a timely challenge to synthetic chemists. Due to the increasing incorporation of fluorine into complex molecules such as pharmaceuticals and agrochemicals, the upgrading of fluorine-dense hydrofluorocarbons and hydrofluoroolefins (HFOs and HFCs) to fluorine containing reactive building blocks is an attractive method to close the fluorine cycle.
In this context, we demonstrate methods to selectively activate sp2 and sp3C–F bonds in fluorocarbons using main group compounds. We have developed efficient methods to chemically upgrade industrially relevant HFOs and HFCs to simple-bench stable silicon compounds. Furthermore, we have advanced the understanding of how to activate strong C–F bonds, by interrogating the reaction mechanisms using computational calculations (DFT).
Version
Open Access
Date Issued
2019-11
Date Awarded
2020-05
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)