In the presence of a catalytic amount of dichlorotris(triphenylphosphine)ruthenium(II), the reactions of arenesulfonyl chlorides with allylphenyl sulfide and allylphenyl selenide proceeded smoothly to give allylphenylsulfone in high yield as well as the corresponding diphenyl disulfide or diphenyl diselenide. An SH2′-type mechanism involving the arenesulfonyl radical is proposed.