NUCLEOPHILIC DISPLACEMENT REACTIONS AT Se(II). REACTION OF ARENESELENENYL CHLORIDES AND 2-CHLOROALKYL PHENYL SELENIDES

Article abstract of DOI:10.1016/S0040-4020(01)96718-3

The products of the title reaction depend upon the relative concentrations of reactants.With equimolar concentrations or an excess of 2-chloroalkyl phenyl selenide, the products are 1,2-dichloroethane and a diaryldiselenide.When excess areneselenenyl chloride is used, the products are a diaryl diselenide and 2-chloroalkyl phenyl selenide dichloride.A mechanism involving nucleophilic displacement at selenenyl selenium is proposed to account for the observed products.Structural changes in the selenide on varying substituents in the 4-position of areneselenenyl chloride has little effect on the rate of the reaction.In the proposed continuum of mechanisms of nucleophilic displacement reactions at Se(II), an S_N2-like transition state best accounts for the data.