Efficient Synthesis of Unsymmetrical Selenides Promoted by Titanocene Perfluorobutanesulfonate/Zinc Catalytic System

In the presence of 10 mol% titanocene perfluorobutanesulfonate (1 center dot H2O center dot THF), reductive cleavage Se-Se bond by zinc dust (1.2 equiv.) at room temperature led to nucleophilic selenium anion species, which reacted with bromoalkanes to afford unsymmetrical selenides in good to excellent yield using commercial tetrahydrofuran (THF) as solvent under N-2 atmosphere. The possible reaction mechanism is that zinc dust reduces Cp2TiIV(OPf)(2) (Pf= SO2C4F9) to produce Cp(2)Ti(III)OPf, which reacts With djaryl diselenides to fonn the intermediate (Cp2TiSeAr)-Se-IV(OPf). Then it further reacts with bromoalkanes to produce unsymmetrical selenides. In this paper, the synthesis of asymmetrical selenides catalyzed by 1 center dot H2O center dot THF/Zn system is first reported. This method has the advantages of mild reaction conditions, simple operation and high yield.