Proton-assisted activation of a Mn III -OOH for aromatic C-H hydroxylation through a putative [Mn V O] species.

Adding HClO 4 to [(BnTPEN)Mn III -OO] + in MeOH generates a short-lived Mn III -OOH species, which converts to a putative Mn V O species. The potent Mn V O species in MeCN oxidizes the pendant phenyl ring of the ligand in an intramolecular fashion. The addition of benzene causes the formation of (BnTPEN)Mn III -phenolate. These findings suggest that high valent Mn species have the potential to catalyze challenging aromatic hydroxylation reactions.