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Wang, Yang. / "October 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 87-92). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract (in English) --- p.III / Abstract (in Chinese) --- p.IV / Abbreviation --- p.V / List of Compounds --- p.VI / List of Figures --- p.IX / Contents --- p.X / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Synthesis and Structure of Half-Sandwich Group 4 Metallocarboranes Containing the Dicarbollyl Ligand --- p.2 / Chapter 1.2 --- Half-Sandwich Group 4 Metallacarboranes Catalyzed Reactions --- p.20 / Chapter 1.2.1 --- Polymerization of Olefins --- p.20 / Chapter 1.2.2 --- Catalytic Dimerization and Hydrogenation of Alkynes --- p.22 / Chapter 1.2.3 --- Catalytic Addition of Amines to Carbodiimides --- p.23 / Chapter 1.2.4 --- Catalytic Transamination of Guanidines --- p.24 / Chapter 1.2.5 --- Catalytic Synthesis of A^-Heterocycles --- p.25 / Chapter 1.3 --- Research Objectives of This Thesis --- p.26 / Chapter Chapter 2 --- Half-Sandwich Group 4 Metallacarborane Monoamindes --- p.27 / Chapter 2.1 --- Introduction --- p.27 / Chapter 2.2 --- Synthesis of Dicarbollyl Ligands Bearing Functional Side Arms --- p.27 / Chapter 2.3 --- Synthesis and Characterization of Half-Sandwich Group 4 Metallacarborane Monoamindes --- p.33 / Chapter 2.4 --- Summary --- p.43 / Chapter Chapter 3 --- Synthesis of 2-Aminoimidazoles Catalyzed by Half-Sandwich Titanacarborane Monoamide --- p.44 / Chapter 3.1 --- Introduction --- p.45 / Chapter 3.2 --- Known Methods for the Synthesis of 2-Aminoimidazole --- p.44 / Chapter 3.2.1 --- Condensations Methods --- p.44 / Chapter 3.2.2 --- Direct Introduction of N at C2 Position --- p.46 / Chapter 3.2.3 --- Heterocyclic Exchange Reactions --- p.47 / Chapter 3.2.4 --- Transition Metal Catalyzed Reactions --- p.48 / Chapter 3.3 --- Results and Discussion --- p.49 / Chapter 3.3.1 --- Synthesis of Propargy 1 Amines --- p.49 / Chapter 3.3.2 --- Synthesis and Characterization of 2-Aminoimidazoles --- p.50 / Chapter 3.3.3 --- Proposed Reaction Mechanism --- p.55 / Chapter 3.4 --- Summary --- p.57 / Chapter Chapter 4 --- Conclusion --- p.59 / Chapter Chapter 5 --- Experimental Section --- p.61 / References --- p.87 / Appendix / Chapter I. --- Publication Based on the Research Findings --- p.93 / Chapter II. --- Crystal Data and Summary of Data Collection and Refinement --- p.94 / Chapter III. --- X-ray crystallographic data in CIF (electronic form)

Imidazo[1,5-a]pyridines are an important and versatile class of N-heterocyclic compounds due to their stability, unique biological, and photochemical properties. Due to the conjugation and charged structure, their properties are extended to conducting electricity and also have electronic properties. They can be used for chelating transition metals especially heavy metals that can be harmful to living things (including human). The aim of this research was to develop more useful imidazo[1,5-a]pyridines which are stable in both free and complexed state. A variety of imidazo[1,5-a]pyridyl compounds was synthesized following three useful methods namely (i) The first route includes the isolation of imine intermediates which were then treated with phosphorus oxychloride in one case and hydrochloric acid in another case as catalysts. Both cases resulted in the yield of the same imidazo[1,5-a]pyridyl compounds. (ii) The second route was the development on the first route for those imine intermediates that could not be isolated and only hydrochloric acid catalyst was used. In both the first and second routes, paraformaldehyde was used for the ringclosure step of the reaction. The last route for the formation of imidazo[1,5-a]pyridyl compounds did not involve the use of the paraformaldehyde reagent. The suitable routes were followed depending on the nature of the targeted products and the reaction yields were moderate to excellent. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg,2010.