Developing sustainable catalytic methods
The global chemical industry produces goods that are essential to our way of life. From commodity chemicals to fine chemicals, pharmaceuticals to agrochemicals, these are products that we cannot do without. The energy demands of the chemical sector are also enormous and given that most of this energy still comes from fossil fuels, the sustainability of this industry and in turn the chemicals on which we rely is a matter of grave concern. Catalysts are without a doubt part of the solution to ensuring this sustainability as they can provide ways of producing these goods that are much less energy intensive. On top of this they also offer benefits such as improved efficiency in terms of product yield, leading to less waste. Developing catalytic methods that fit this criterion, as well as the additional need of being economically viable is however not trivial and presents many challenges. This thesis explores two approaches to increasing the industrial appeal of two different types of catalytic systems. The first chapter deals with (thio)urea organocatalysts and using bespoke Molecularly Imprinted Polymers (MIPs), with the goal of allowing the catalysts to be recycled. The second chapter involves the development of a new Pd(II) catalyst for the Wacker-type oxidation of alkenes using tert-butyl hydroperoxide (TBHP) as the oxidant. The mechanisms of catalyst deactivation are investigated with the goal of being able to perform this type of transformation using lower loadings of catalyst than existing methods allow. The third and final chapter is a preliminary investigation into the thermal behaviour of Pd(II) catalysed Wacker-type oxidations using TBHP. Multiple calorimetric methods are used to examine the viability of carrying out this type of transformation safely on a larger scale.
Networked Digital Library of Theses and Dissertations