Oxidative ortho C-C coupling of 4-ethylphenol by dual substrate activation at a bioinspired dicopper complex--trapping of an unusual oligophenolic Cu6 species.

Bioinspired dual activation: Dual activation within the bimetallic pocket of a bioinspired dicopper(II) complex suitably places two phenolato substrates for preferred ortho-ortho coupling. Spectroscopic data and the molecular structure of a unique Cu(6) complex isolated from the reaction mixture reveal a novel terphenolato ligand and provide a clue about the activation mechanism (see picture).

Selective benzylic C-C coupling catalyzed by a bioinspired dicopper complex.

A highly preorganized bioinspired dicopper complex with imidazole ligation catalyzes the selective benzylic para-C-H activation of 2,4,6-trimethylphenol under aerobic conditions, yielding either the stilbenequinone or 4-methoxymethyl-2,6-dimethylphenol depending on the solvent used.

Oligonuclear copper complexes of a bioinspired pyrazolate-bridging ligand: synthesis, structures, and equilibria in solution.

The synthesis of a new bioinspired dinucleating ligand scaffold based on a bridging pyrazolate with appended bis[2-(1-methylimidazolyl)methyl]aminomethyl chelate arms is reported. This ligand forms very stable copper complexes, and a series of different species is present in solution depending on the pH. Interconversions between these solution species are tracked and characterized spectroscopically, and X-ray crystallographic structures of three distinct complexes that correspond to the species present in solution from acidic to basic pH have been determined.