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.