Regioselective iodination of chlorinated aromatic compounds using silver salts

The iodination of chlorinated aromatic compounds using Ag2SO4/I2, AgSbF6/I2, AgBF4/I2, and AgPF6/I2 offers access to iodoarenes that are valuable intermediates in organic synthesis. Specifically, iodination of phenols, anisoles, and anilines with a 3,5-dichloro substitution pattern preferentially yielded the ortho, para, and para iodinated product, respectively. In the case of chlorobenzene and 3-chlorotoluene, AgSbF6/I2, AgBF4/I2, and AgPF6/I2, but not Ag2SO4/I2, selectively introduced the iodine in para position to the chlorine substituent.