The authors observed the effect of electrophilic assistance of mercury(II) in a new reaction involving the oxidative addition of RI to PtCl//4**2** minus , which, as is shown, reduces to the realization of transition state C. The later rigorously proves the S//N//2 mechanism of the reaction presented by the authors at least for conditions of electrophilic assistance in cleaving the carbon-iodine bond. The kinetic equation for a pathway that includes the reaction of MeI simultaneously with platinum(II) and mercury(II) is given.