Rhodium and iridium complexes of Fischer and N-heterocyclic carbenes: Synthesis and reactivity

This dissertation concerns the synthesis and properties of Fischer and N-heterocyclic carbene complexes of rhodium and iridium. Chapter two describes the synthesis of Fischer carbene complexes of iridium, derived from aminopyridines. The mechanism of formation, via a double C-H activation, is investigated. Stoichiometric C-C coupling reactions with alkenes, alkynes, and enones are described. In chapter three we explore the origin of anion-dependant selectivity in the formation of normal and abnormal N-heterocyclic carbene complexes of iridium. Chapter four describes the synthesis of an abnormal N-heterocyclic carbene ligand of intermediate electron-donating power. The effect of varying the electron-donating power of abnormal N-heterocyclic carbene ligands in alkyne hydrosilylation is examined. In Chapter five the synthesis of an isosteric series of N-heterocyclic carbene ligands with varying electron-donor properties, and their neutral and cationic iridium complexes is described. An unusual intramolecular C-H activation, which is at equilibrium at room temperature, is described. Chapter six describes the synthesis of iridium complexes with two monodentate N-heterocyclic carbene complexes. Complexes combining normal N-heterocyclic carbene ligands, abnormal N-heterocyclic carbene ligands, and triazole-derived N-heterocyclic carbene ligands are described.