Synthesis of new tripodal ligand: N,N-bis[(1,5-dimethylpyrazol-3-yl)methyl]benzylamine.: Catecholase activity of two series of tripodal ligands with some copper (II) salts

A synthesis of new tripodal ligand: N,N-bis[(1,5-dimethylpyrazol-3-yl)methyl]benzylamine is reported. Copper (II) complexes of compounds: N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)-amines (L1–L5) and N,N-bis[(1,5-dimethylpyrazol-3-yl)methyl]-amines (L6–L9) were examined for their catalytic activities. The dioxygen complexes of copper (II) were generated in situ by stirring copper salts and the tridentate pyrazole ligands. It has been found that the oxidation of 3,5-di-tert-butylcatechol is very efficient to give 3,5-di-tert-butylquinone. Ligand structure has proven critical in controlling not only the formation of complexes but also their subsequent reactivity. The nature of junction between the pyrazolic rings and the benzene have a large effect on the oxidation reaction rate.