RS Fellow - EPSRC grant (2014): Application of Tandem Non-Covalent Interactions to the Development of New Enantioselective Reactions

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A primary goal of organic chemists is the construction of molecules for applications as diverse as medicines, new materials and biomolecules. The field is constantly driven by the need for new, more efficient methods as well as ways to access molecules which may have previously been impossible. The most important tool at an organic chemist's disposal is undoubtedly catalysis, whereby the use of a small amount of a custom-designed catalyst can permit a reaction to occur under much milder conditions than otherwise, or opens up new chemical pathways altogether. For this reason, innovation in catalysis is central to innovation in organic chemistry. Nature's catalysis is performed by enzymes; evolution has made them phenomenally efficient. Often playing a leading role in enzymatic processes are 'hydrogen bonds', special types of electrostatic attraction which are important in facilitating the chemical reaction between two molecules by bringing them into close proximity with one another or by stabilising the pathway leading to product formation. My research seeks to employ these same interactions, but in the context of small molecules which we can readily synthesise and handle in the lab. This approach to catalysis is very exciting as it is still in its infancy yet offers exciting opportunities for both activation and control. This project will seek to take inspiration from a distinct field within chemistry called Supramolecular Chemistry, which explores the behavior of large molecules which are assembled from smaller ones using multiple weak 'temporary' interactions working in tandem. Hydrogen bonds are very important in this regard but there are a number of other key interactions such as ion pairs and pi-cation interactions which have been shown to be powerful in building up molecular structures. It is our aim to apply several of these interactions together in tandem to design new catalysts that will bind with our reactant in a very well defined orientation. The catalyst will also induce the substrate to react with another molecule, allowing the selective synthesis of one mirror image of a molecule over the other (so-called enantiomers). This is a very important pursuit in science, since the inherent 'handedness' of biological systems means that the different mirror image forms of chiral molecules often have very different effects in the body. This is of particular importance in pharmaceutical applications.