The treatment of (E)-3, 4-dimethoxycinnamic acid with ceric ammonium nitrate in trifluoroacetic acid afforded (E)-1, 2-dimethoxy-4-nitro-5-(2-nitroethenyl) benzene in 79% yield. The unusual ipso substitution of the carboxylic acid moiety by a nitro functional center illustrated a new reaction manifold of cerium (IV). Six cinnamic acids were examined to ascertain the generality of the transformation. The bidentate nitrato structure of the metal ...
