Abstract
The overall aim of this project was to investigate ways of improving current tritiation procedures for organic compounds. More specifically we have concerned ourselves with the hydrogenation of unsaturated carbon-carbon bonds using both stable deuterium and radioactive tritium isotopes. Initial chapters describe the use of commercially available rhodium and iridium based homogeneous hydrogenation catalysts, for labelling a variety of substrates using deuterium gas. Labelling patterns and mechanistic details are discussed with reference to common heterogeneous catalysts such as Pd/C. In the following chapters the use of solid hydrogen sources and the concept of hydrogen transfer hydrogenation are discussed as an alternative approach to labelling compounds. The benefits of using formates as hydrogen sources and the results of labelling studies are shown, together with novel labelling patterns observed with selected substrates. In an extension to this work we have performed microwave enhanced hydrogen transfer reactions. The advantages of microwave irradiation over thermal heating are highlighted. The final chapter is concerned with the tritiation of a number of substrates using tritiated formate salts under thermal and microwave conditions. The results obtained for the rhodium catalysed asymmetric hydrogenation of acetamidocinnamic acid, a precursor to phenylalanine, using tritium gas and tritiated formate are also presented.