Mechanistic Insights into the -Defluorination-Hydroxylation of 2-Halophenolates Promoted by a Bis(μ-oxo)dicopper(III) Complex.

C-F bonds are one of the most inert functionalities. Nevertheless, some [CuO] species are able to defluorinate-hydroxylate -fluorophenolates in a chemoselective manner over other -halophenolates. Albeit it is known that such reactivity is promoted by an electrophilic attack of a [CuO] core over the arene ring, the crucial details of the mechanism that explain the chemo- and regioselectivity of the reaction remain unknown, and it has not being determined either if Cu(η:η-O) or Cu(μ-O) species are responsible for the initial attack on the arene. Herein, we present a combined theoretical and experimental mechanistic study to unravel the origin of the chemoselectivity of the ortho-defluorination-hydroxylation of 2-halophenolates by the [Cu(O)(DBED)] complex (DBED = ,'-di--butylethylenediamine). Our results show that the equilibria between (side-on)peroxo () and bis(μ-oxo) () isomers plays a key role in the mechanism, with the latter being the reactive species. Furthermore, on the basis of quantum-mechanical calculations, we were able to rationalize the chemoselective preference of the [Cu(O)(DBED)] catalyst for the C-F activation over C-Cl and C-H activations.