Formation of a peri‐Bridged Phosphonio‐Naphthalene by Cu‐Mediated Phosphine–Aryl Coupling

: The peri-iodo naphthyl phosphine 1 reacts with CuI to give the peri-bridged phosphonio-naphthalene 2, which has been fully characterized (multi-nuclear NMR, MS, XRD). The outcome of the reaction differs markedly from that observed with gold. A two-step pathway involving P-assisted C-I oxidative addition to copper, followed by P-C reductive elimination is shown to be energetically feasible by DFT calculations.