Utilization of the Fe-II-H2O2 system in the presence of diphenyl diselenide, phenylselenol, diphenyl disulfide and thiophenol converts saturated hydrocarbons into the corresponding alkyl phenyl selenide or alkyl phenyl sulfide. Starting with Fe-III-H2O2 no reaction occurs in presence of diphenyl diselenide but the Gif(IV) system (Fe-II/O-2-radical-anion) is able to produce phenyl seleno derivatives along with the oxidation products. The presence of sodium sulfide with the Fe-II and Fe-III-H2O2 systems affords some dicyclohexyl disulfide. Mechanistic studies suggest than all these reaction are based on the Fe-II-Fe-IV manifold with a suitable carboxylic acid as ligand. Copyright (C) 1996 Elsevier Science Ltd.