Selective Functionalization of Poly(4-methylstyrene)

The oxidation of poly(4-methylstyrene) with cerium(IV) and cobalt(III) complexes in glacial acetic acid introduces functional groups selectively into the 4-methyl position. The polymer backbone methine groups are almost completely protected from oxidation due to stereo-electronic effects. The reaction proceeds by double electron transfer to give intermediate polymeric benzyl cations. These combine with nucleophiles present in the reaction …