Introduction of a Hydroxy Group at the Para Position and N-iodophenylation of N-arylamides Using Phenyliodine(III) Bis(trifluoroacetate)

The reaction of anilides with phenyliodine(III) bis(trifluoroacetate) (PIFA) in trifluoroacetic acid (TFA), TFA-CHCl3, or hexafluoroisopropyl alcohol (HFIP) is described. When the acyl group of the anilide is highly electronegative, such as trifluoroacetyl, or the phenyl group is substituted with an electron-withdrawing group, the 4-iodophenyl group is transferred from PIFA to the amide nitrogen to afford acetyldiarylamines. On the other hand, when the acyl group contains an electron-donating function, such as 4-methoxyphenyl, or the phenyl group is substituted with an electron-donating group, a trifluoroacetoxy group is transferred to the para position of the anilide aromatic ring. This group is hydrolyzed during workup to produce the corresponding phenol.