Transition Metal Catalyst, Solvent, Base Free Synthesis of Diaryl Diselenides under Mechanical Ball Milling

A convenient, efficient, and general procedure for the synthesis of diaryl diselenides has been developed by the reaction of aryl diazonium tetrafluoroborates and Potassium Selenocyanate on the surface of alumina under ball-milling in absence of any solvent, transition metal catalyst and base in room temperature. A wide range of functionalized diaryl diselenides are obtained in high purity and high yield by this procedure. Background: Synthesis of diaryl diselenides was restricted into only few Cu-catalyzed C-Se Cross coupling protocol where use of ligands, high reaction temp, long reaction time were required Objective: To achieve a sustainable protocol for the synthesis of diaryl diselenides Method: Reaction of aryl diazonium fluoroborate with KSeCN was successfully performed under ball milling in absence of any ransition metal catalyst, ligands, base and external heating to get diaryl diselenides. Results: A library of diaryl diselenides were obtained in good yields with different functional groups. Conclusion: First transition metal free protocol for the synthesis of diaryl diselenides has been developed successfully.