Complete σ* intramolecular aromatic hydroxylation mechanism through O2 activation by a Schiff base macrocyclic dicopper(I) complex.

In this work we analyze the whole molecular mechanism for intramolecular aromatic hydroxylation through O2 activation by a Schiff hexaazamacrocyclic dicopper(I) complex, Cu(I) 2(bsH2m). Assisted by DFT calculations, we unravel the reaction pathway for the overall intramolecular aromatic hydroxylation, i.e., from the initial O2 reaction with the dicopper(I) species to first form a Cu(I)Cu(II)-superoxo species, the subsequent reaction with the second Cu(I) center to form a μ-η(2):η(2)-peroxo-Cu(II) 2 intermediate, the concerted peroxide O-O bond cleavage and C-O bond formation, followed finally by a proton transfer to an alpha aromatic carbon that immediately yields the product Cu(II) 2(bsH2m-O)(μ-OH).