Benzylic Ligand Hydroxylation Starting from a Dicopper μ-η2:η2 Peroxo Intermediate: Dramatic Acceleration of the Reaction by Hydrogen-Atom Donors

Benzylic Ligand Hydroxylation Starting from a Dicopper μ-η2:η2 Peroxo Intermediate: Dramatic Acceleration of the Reaction by Hydrogen-Atom Donors: "

Radicals in directed pathways: The μ-η²:η² peroxo Cu^II₂ intermediate 1 shows a much faster benzylic ligand hydroxylation than systems without phenol. This novel reactivity can be further accelerated by addition of external H-atom donors such as TEMPO-H. The results imply initial H-atom transfer leading to the formation of phenoxyl radicals. A highly reactive copper oxyl intermediate is then formed, which inserts oxygen into the benzylic CH bond.

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