Development of Ruthenium based catalytic systems for C-H bond activation/arylation of aryl pyridines

Abstract

This thesis comprises of six chapters which deal with the designing and development of ruthenium based efficient catalytic systems for C-H bond activation of aryl pyridines. The first chapter of this thesis narrates the brief introduction of the research topic and extensive literature survey about the previous developments in the field of transition metal catalyzed C-H bond activation/functionalization reactions. The subsequent chapters illustrate the synthesis, characterization and catalytic activity of designed arene-ruthenium complexes based on N,O/O,O donor ligands. The main purpose of the thesis is to develop highly active and efficient catalytic system for ortho C-H bond activation/arylation of 2-phenylpyridines and to study the mechanistic pathways of catalyzed reaction using various instrumentation techniques. In the last chapter, concluding remarks along with the future speculations of the present research are briefly described. The principal objectives of the present study are: • To design and synthesize the highly efficient, competent, and robust catalytic system based on water soluble arene-Ru(II) complexes containing monodentate nitrogen-based ligands for ortho C-H bond arylation of 2-phenylpyridine. • To synthesize water soluble Ru(II) based molecular catalysts coordinated with bidentate N,O/N,N donor ligands to study their structure activity relationship towards ortho C-H bond activation/arylation of 2-phenylpyridine. • To develop an efficient catalytic system with readily available biomass derived O,O donor ligands, employed as additives, to achieve enhancement in the rate of Ru(II) catalyzed ortho C-H bond activation/arylation reaction. • To establish a highly active catalytic system with N,O donor ligands such as 2-hydroxypyridine based ligands which acts as a promoter in achieving high selectivity and enhancement in the rate of Ru(II) catalyzed ortho C-H bond activation/arylation reaction of 2-phenylpyridine. • To gain mechanistic insights into the reaction using various instrumentation techniques to deeply understand the reaction pathway.