Metal-Free Synthesis of Phenol-Aryl Selenides via Dehydrogenative C-Se Coupling of Aryl Selenoxides with Phenols

Herein, we disclose the synthesis of diaryl selenides through an unexpected C-Se coupling between aryl benzyl selenoxides and phenols. The synthetic significance of the method is that it provides a mild, rapid, and metal-free access to organoselenides in high yields with excellent functional group tolerance. This coupling of aryl benzyl selenoxides reveals a completely new reaction possibility compared with aryl sulfoxides. We also probed the reaction mechanism of this unexpected transformation through experimental studies and revealed a special Se(IV)-Se(III)-Se(II) reaction pathway.