SYNTHETIC MIMICS OF TYROSINASE - CATECHOLS FROM ORTHOSUBSTITUTED, METASUBSTITUTED AND PARASUBSTITUTED PHENOLS AND COPPER(I) COMPLEXES

Catechols are obtained by reacting phenols bearing electron-withdrawin g substituents at C-2, C-3 and C-4 and two copper(I) complexes, follow ed by dioxygen oxidation. A preference for the 3,4-catechol over the 2 ,3-catechol is observed with 3-substituted phenols. Ortho substituted phenols give very low yields in catechol. A binuclear mu-eta(2):eta(2) -peroxocopper(II) phenolate complex is suggested to be the intermediat e. Force field calculations permit explanation of the observed reactiv ity and the regiochemistry noted with meta-substituted compounds.