Applications of five-membered ring products of cyclometalation reactions as anticancer agents

The use of metal compounds as anticancer agents is one of the applications of the five-membered ring products of cyclometalation reactions, including those with Pt, Pd, Rh, Ir, Ru, Os and Au. The coordinating atoms in these anticancer agents are mainly N and, in very few cases, P, S and O. The substrates used for these cyclometalation reactions are mainly pyridine ring compounds, such as 2-phenylpyridines, benzo[ h ]quinolines, 2,6-diphenylpyridines and so on. The ancillary ligands used are bipyridines, 1,10-phenathrolines, 2,6-bispyridylpyridine, N -heterocyclic carbenes and so on. The platinum compounds of 2,6-phenylpyridylpyridine CNN pincer N -heterocyclic carbene, the gold compounds of 2,6-diphenylpyridine CNC pincer alkylphosphine or N -heterocarbene, and the osmium compounds of 2-phenylpyridine, phenyloxazole, m -bispyridylbenzenes cyclometalated 1,10-phenanthrolines or 2,6-bispyridylpyridines show very high cytotoxicity values compared to those of cisplatin.