anodic oxidation proceeds either via phosphiniumradicalcations, which then attack the arenes electrophilically, or via arene radicalcations, which add the trialkylphosphite as nucleophile. Aryl phosphonates are also obtained in good yield by chemical oxidation with peroxodisulfate/AgNO3 in acetonitrile/water or glacial acetic acid. The diethylphosphinium radicalcation, formed from diethylphosphite by