 While the Cu(III) species activates the aromatic ring, the amide oxygen attacks the "ortho" position, breaking the aromaticity and allowing cupration at the "meta" position.The intermediate then rearomatizes with base and undergoes reductive elimination to afford the "meta"-arylated product and regenerate the active Cu(I) catalyst.Alternatively, Li and Wu, based on DFT calculations, proposed a mechanism involving a "Heck-like four-membered-ring transition state".