Towards New Catalytic Antioxidants: A Simple and Mild Synthesis of Selenenylsulfides

A new methodology for the synthesis of small molecules containing the S-Se bond is reported. Aryl- and alkyl-selenols react smoothly with N-thiophthalimides to afford the corresponding selenenylsulfides through a clean SN2 path occurring at the sulfur atom. The reaction proceeds under very mild conditions in DMF in absence of catalysts for most of the substrates. The scope of the reaction was found to be broad, allowing a wide series of selenols and N-thiophtalimides to be efficiently employed in this procedure. Owing to the instability of the S-Se bond, selenenylsulfides exhibited a remarkable tendency to disproportionate to the corresponding symmetric diselenides and disulfides. Preliminary evaluation of the catalytic antioxidant properties of novel selenenylsulfides showed their behaviour as GPx mimics.