The Reaction Involving One Electron Transfer in Key Step. NO2-Catalyzed Halogenation of Polycyclic Aromatic Compounds with Metal Halides

In the co-existence of catalytic amount of nitrogen dioxide and oxygen, aluminum halide, titanium(IV) halide, and some other metal halides have been found to be highly selective and regiospecific halogenating agents for polycyclic aromatic compounds, including anthracene, pyrene, benz[a]anthracene, chrysene, phenanthrene, naphthalene, triphenylene, fluoranthene, benzo[b]thiophene, and dibenzothiophene.