Design, synthesis and characterization of arene-Ru(II) complexes based on nitrogen donor ligands : catalytic reactions and mechanistic investigations

Abstract

This thesis comprises of six chapters, which deal with the designing and development of homogeneous complexes for various catalytic applications. The first chapter describes the background of transition metal based homogeneous catalysts, and motivation to design nitrogen donor ligands based complexes for important catalytic reactions. In the subsequent chapters, synthesis, characterization, and catalytic activities of newly synthesized arene-Ruthenium(II) complexes based on readily available nitrogen donor ligands have been illustrated. Main goal of this thesis is to understand the mechanism of catalytic reactions performed with the synthesized complexes. The synthesized complexes have been successfully employed for several catalytic organic transformations such as C-N coupling, C-C coupling, hydration and hydrogenation reactions under ambient reaction conditions. In the last chapter, concluding remarks and future prospects of devoted research are briefly mentioned. The prime objectives of the present study are as following, • To design and develop a highly efficient, environmentally benign, and robust catalytic system based on phosphine-free Ru(II) complexes, containing nitrogen donor ligands for the one-pot primary aldehydes to amides in aqueous aerobic conditions. • To synthesize molecular catalysts based on water-soluble arene-Ru(II) complexes containing substituted aniline ligands for the catalytic homocoupling of arylboronic acids in water and to investigate the mechanistic pathway of the catalytic reaction. • To design and synthesize the molecular catalysts based on Ru(II) complexes containing iminopyridine ligands and to explore the effect of non-coordinating pendent groups on the catalytic activity for the hydration of terminal alkynes to methyl ketones. • To gain insights into the mechanism of half sandwich Ru(II)-complexes catalyzed chemoselective transfer hydrogenation of nitro compounds into corresponding amines.