Solvent directed electrophilic iodination and phenylselenenylation of activated alkyl aryl ketones

A mixture of molecular iodine and phenyliodine(III) bis(trifluoroacetate) (BTI) in CH3CN (or CH3OH) iodinates the aromatic ring of some activated alkyl aryl ketones. A different outcome results if PhSeSePh is used instead of I2 in the presence of BTI. In CH3CN the aromatic phenylselenenylation is still observed while in CH3OH the formation of α-phenylseleno ketones occurs followed by the conversion of these intermediates into the corresponding α,α-dimethoxycarbonyl compounds, in moderate to good yields.