PhICl2 Is Activated by Chloride Ions

A study on the potential activating role of pyridine in the electrophilic chlorination of anisole by PhICl 2 has led to the discovery that soluble sources of chloride ions activate PhICl 2 in the reaction at catalytic loadings, greatly increasing the rate of chlorination. It is further shown that presence of chloride increases the rate of decomposition of PhICl 2 into PhI and Cl 2 . The specific mechanism by which chloride induces electrophilic chlorination and decomposition of PhICl 2 remains an open question.