The formation of biaryl bonds is one of the most important processes in organic chemistry due to the appearance of this motif in numerous natural products, pharmaceuticals, agrochemicals, dyes and chiral catalysts and as such remains an area of intensive research. 1 The oxidation of aromatic organocuprates is known to give biaryls. 2 Such cuprates have been formed by a halogen–metal exchange between an aryl halide and an alkyl lithium 2c or ...