Copper(II)–acid co-catalyzed intermolecular substitution of electron-rich aromatics with diazoesters

The intermolecular aromatic substitution of N,N-dialkylanilines and alkoxybenzenes with diazoesters is shown to proceed in the presence of catalytic amounts of both copper(II) salt and acid (Lewis or Brønsted). This method is a mild and rare metal-free C–C bond formation reaction between aromatic (sp2) and aliphatic (sp3) carbons.