Recyclable hybrid Rh and Ir catalysts for C-X bond formation

Well defined carbon-based catalyst scaffolds have the potential to provide economical and practical routes to a range of high value compounds due to their well defined nanostructure, relatively defect free surfaces, large surface areas and resistance to oxidation. We are currently exploring this area of research by anchoring highly efficient homogeneous catalysts onto a range of robust carbon supports. We have recently developed a convenient method of covalently attaching homogeneous Rh(I) complexes onto glassy carbon electrodes. The tethered complexes were demonstrated to catalyse a hydroamination reaction with an extremely high turnover number (>89,000). Here we present our latest results in this area, describing catalysts that can promote several different reactions with improved activity and increased stability over multiple reaction cycles. To effect this we incorporated more strongly coordinating donors such as triazoles and N-heterocyclic carbenes into the design of the bidentate ligands (eg. 2-3). Using this new series of Rh(I) and Ir(III) hybrid complexes, we are investigating their efficiency and recyclability in hydrosilylation and N-alkylation reactions. Finally, we discuss our research into immobilizing catalysts onto other nanocarbon-based materials.