Exploiting Chalcogen Bonding and Non-Covalent Interactions in Isochalcogenourea Catalysis: Catalyst Preparation, Mechanistic Studies and Applications

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The ability to synthetically manipulate and prepare specific molecular structures with defined bespoke properties is the main goal of synthetic chemistry, with applications that span the breadth of contemporary science ranging from materials chemistry to chemical biology. Catalysis provides society with efficient industrial processes that minimize energy consumption, waste production and the formation of harmful by-products. This research proposal aims to bring together these two areas, through developing a range of effective catalysts and generating an understanding of their fundamental properties. The developed catalysts will be used to uncover new and effective routes to prepare high value (chiral) materials that will be of interest to the global synthetic community as well as the pharmaceutical and agrochemical industries. This proposal aims to generate a fundamental understanding of how a particular class of simple organic molecule, known as an isochalcogenourea, is able to catalyze a wide range of selective chemical transformations. Through developing an understanding of how each step in a particular process works, and by comprehending how the rate of each step if effected by a change in catalyst structure, we hope to reveal the factors that provide control in the products formed and ultimately lead to more effective reaction processes.The use of organic materials as catalysts is often grouped under the term "organocatalysis". One of the main advantages of this approach is that typical transformations may be performed under relatively mild, 'greener' conditions, thus offering key sustainability benefits. By contrast, catalysis using metals usually requires more stringent conditions, including the rigorous exclusion of moisture and oxygen as well as the use of typically expensive metal systems. However, metal-derived catalyst systems still substantially outperform organocatalytic analogues; with high catalyst loadings still necessary in the majority of organocatalytic reactions. As a result, there has been limited uptake to date of organocatalytic approaches in industrial settings despite the clear 'green' advantages. A step change in catalyst efficiency will be required before the broader usage of organocatalytic approaches occurs. A more detailed mechanistic understanding of the inter-relation between catalyst structure and product is essential to underpin future developments. This proposal will demonstrate a fundamental quantitative understanding of the roles of isochalcogenoureas in catalysis. Through understanding these processes we will deliver a series of catalysts that can be used at very low concentration to allow synthetic access to the broad range of scaffolds required by the chemical and pharmaceutical industries.