Calix[6]arene-based models for mono-copper enzymes: a promising supramolecular system for oxidation catalysis

摘要

A novel supramolecular system that mimics the mono-copper site of enzymes is described. It is based on a calix[6]arene presenting either three pyridine (Py) or three imidazole (Im) groups that coordinate the copper center. Whereas Cu(I) is tetrahedral, Cu(II) is 5-coordinate. In both cases however, the Cu complexes possess a labile site located inside the calixarene cavity. A comparative study of the Py- and Im-based systems is presented in terms of chemical behaviour, electrochemistry and reactivity in the presence of hydrogen peroxide. Hence, the Py-based Cu(III) complex appears as the most interesting catalyst for the oxidation of aromatics and alcohols.