Aromatic iodination with the I2-HgX2 combination

Article abstract of DOI:10.1016/S0040-4020(01)90424-7

The reaction of differnt aromatic compounds 1a-1t with iodine and a mercury(II)-salt 2 [mercury(II) chloride, nitrate or triflate] (1:1:1 molar ratio) in dichloromethane at room temperature leads to the corresponding iodoarene 3, the obtained regiochemistry being the expected. Concerning the mercury(II) salt, the observed reactivity decreased in the series triflate > nitrate > chloride according to their ionic character. An activation of the iodine molecule by the mercury(II) salt followed by a S(E) reaction with the aromatic compounds is postulated as the possible mechanism.