Functional Conjugable Diselenides through Sequential Dehydrogenative Dimerization Cascade

Abstract

Given the biological relevance and materials utility of diselenide scaffolds, we report a structurally diverse unprecedented class of functional diselenides, formimidoester diselenides and formimidothioester diselenides, that are synthesized from isoselenocyanates and alcohols/thiols using solvent-free and transition-metal-free single-pot cascade dehydrogenative dimerization strategies, employing hydrogen peroxide as an oxidant. As proof of concept, we demonstrate that the resulting diselenides are stable and amenable to molecular conjugation, enabling postsynthetic molecular attachment such as carbohydrates and steroids. The practicality of the method is further demonstrated by successful larger-scale synthesis. The proposed reaction mechanism is supported by the DFT-derived free energy profile, which provides deeper insight into the mechanistic aspects of the processes.