Reactions of aryl alkyl ketones with methanol solution of elemental iodine and 1-fluoro-4-chloromethyl-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor F-TEDA-BF4) result in the formation of corresponding alpha-iodo ketones, while switch over of the regioselectivity can be directed by using acetonitrile as the solvent and selective iodination of the aromatic site of target molecules is thus achieved.