Synthesis and properties of palladium complexes including 4-nitrophenyl group

N-heterocyclic carbenes (NHC) are stable systems that act as auxiliary ligands for organometallic complexes. NHCs have great potential in organocatalysis due to their strong σ donor, weak π receptor, great electronic flexibility and also the ease of control of the steric effects of the substituents on the nitrogen atom. NHCs have a wide range of applications for both organocatalyst and medical purposes on their own or with transition metal complexes. Platinum-containing complexes such as cisplatin and carboplatin show effective cytotoxic activity on cancer therapies. Complexes containing palladium also have a natural potential as anticancer agents due to their structural resemblance to these platinum complexes. For the reasons mentioned above, the studies conducted and the results obtained in this thesis can be summarized under eight headings: xiv 1) 2-(4-nitrophenyl)ethyl substituted benzimidazolium salts (1a-f) were synthesized as carbene precursors and their structures were characterized by suitable spectroscopic methods. 2) NHC-Pd(II)-3-chloropyridine (Pd-PEPPSI) complexes (2a-f) were synthesized from the reaction of carben precursors (1a-f), PdCl2 and 3-chlorpyridine, and their structures were characterized by suitable spectroscopic methods. 3) NHC-Pd(II)-pyridine complexes (3a-e) were synthesized from the reaction of carbene precursors (1a-f), PdCl2 and pyridine, and their structures were characterized by suitable spectroscopic methods. 4) From the reaction of NHC-Pd-pyridine complexes (3) with morpholine, NHCPdBr2- morpholine (4a-e) complexes were obtained. The structures of the synthesized complexes are illuminated by suitable spectroscopic methods. 5) From the reaction of NHC-Pd-pyridine complexes (3) and triphenylphosphine, NHC-PdBr2-triphenylphosphine (5a-d) complexes were obtained and their structures were illuminated by appropriate spectroscopic methods. 6) The NHC-Pd-pyridine complex 3d and the 2-aminopyridine reaction yielded the NHC-PdBr2-2-aminopyridine (6) complex. The structure of the synthesized complex is illuminated by appropriate spectroscopic methods. 7) Enzyme inhibition activities of 1,3-disubstituted benzimidazolium salts (1) with 2- (4-nitrophenyl) ethyl substituents were investigated. 8) The catalytic activities of NHC-Pd(II)-3-chloropyridine (2) complexes in direct arylation reactions were investigated. KEY WORDS: N-heterocyclic carbene precursors; benzimidazole; NHC-Pd (II) -pyridine (Pd-PEPPSI) complexes; Direct Arilation; Enzyme inhibition, X-crystallography.