Gold-mediated C-I bond activation of iodobenzene.

Controversy resolved! A combination of gas-phase ion-molecule reactions and theoretical studies confirm bisligated mononuclear Au(I) complexes are unable to undergo oxidative addition of iodobenzene for Sonogashira coupling, but that the ligated gold clusters Au(3)L(n) (L=Ph(2)P(CH(2))(n)PPh(2); n=3-6) activate the C-I bond. DFT calculations on the transition states show that the linker size n tunes the cluster reactivity.