Perfluorinated xylenes and perfluoro-para-cymene undergo hydrodefluorination under the action of Zn (Cu)-DMF-H2O. Hydrogen enters mainly at the benzyl position of para- dialkybenzenes and at the para position to perfluoroalkyl groups of perfluorinated ortho-and meta-xylenes. The process presumably involves radical anions as intermediates. A product of perfluoro-4-methylbenzyl radical trapping by hexene-1 was obtained. Quantum- ...