Syntehesis , characterisation and investigation of catalytic activity of coperN-heterocyclic carben complexes

N-heterocyclic carbenes (NHCs), which have attracted great interest of many researchers in recent years, have emerged as indispensable ligands in transition metal coordination chemistry. As a result of these studies, NHCs have become very important ligands in organometallic chemistry and many organic catalytic transformations. The inherently strong σ-donor ability of NHCs with an unshared electron pair on an inherited sp2-hybridized carbon provides exceptional binding affinities to metal centers. In addition, both electron transfer from the carbene p-orbital by π-backbond and electron transfer from the carbene p-orbital to the metal as a π-donor contribute to metal-ligand binding. Due to the strong -donor weak -acceptor properties of N-hetrocyclic carbenes, it provides steric hindrance with higher electron density in and around the metal center compared to its analogues, phosphine ligands. Thanks to these superior properties, M-NHC complexes exhibit very good catalytic performance with high stability in catalytic reactions. The synthesis of organic compounds by organic transformation reactions in the presence of different metal complexes is very important for industry and academia. The synthesis of 1,2,3-triazoles under mild reaction conditions via Cu-NHC catalysis is very important in the synthesis of substituted triazoles used in many fields, especially in pharmacy. Cu-NHC complex catalysedreaction of synthesis of substituted triazoles in water under normal atmospheric conditions is a very economical and environmentally friendly reaction in manner to the catalyst used and the mild reaction conditions. Since the use of Cu-NHC complexes in this field is very limited, the development of new generation Cu-NHC complexes in this field is very important for academia and industry. For these reasons, within the scope of this thesis, the synthesis of substituted ring-expanded NHC precursors and their copper complexes were carried out and catalytic activities of these Cu-NHC complexes in Huisgen 1,3-cycloaddition reactions were investigated.