Binuclear copper complex [{Cu(Sal) (NCMe)} ] (Sal=salicylate) was found to be an active catalyst for the aerobic oxidation of N-aryl tetrahydroisoquinolines to the corresponding iminium ions, which could be trapped by a wide range of nucleophiles to form coupled products. The reactions took place under 1 bar of O at room temperature with 1 mol % of the copper catalyst being sufficient in most cases, and are considerably accelerated by catalytic chloride anions. Mechanistic studies show that the Cu dimer oxidizes the amine to the iminium ion, and this two-electron process requires O , whereby the resulting Cu is concomitantly reoxidised back to Cu . Various lines of evidence suggest that the oxidative coupling reaction is turnover-limited by the step of iminium formation, and it is this step that is promoted by the chloride anion. Since it is more efficient than and mechanistically distinct from the well-studied simple copper salts such as CuBr and CuCl , the binuclear copper catalyst provides a new tool for oxidative coupling reactions.

A binuclear copper‐salicylate complex, [Cu(Sal)2(NCMe)]2 (Sal=salicylate), was found to be an active catalyst for the oxidation of N,N‐dimethylanilines by O2, affording the corresponding N‐methyl‐N‐phenylformamides as major products. The reactions were carried out with a O2 balloon and the S/C (substrate/catalyst ratio) of the model reaction could be up to 1×105, providing a practical and highly efficient catalytic protocol for accessing N‐methyl‐N‐phenylformamides.

A binuclear copper complex bearing a simple salicylate ligand catalyses the efficient cleavage of styrenes into ketones and aldehydes with O2 as the oxidant. The reaction works under an atmosphere of O2 (balloon) with 0.5 mol% of catalyst and could be performed on a gram scale, providing an alternative to ozonolysis.

Aryl radicals produced by irradiation of diaryliodonium salts with visible light under the catalysis of [Ru(bpy) 3 ] 2+ undergo coupling with a wide range of arenes and heteroarenes, affording various biaryls through direct C-H arylation at room temperature.