Unexpected C-Se cross-coupling reaction: copper oxide catalyzed synthesis of symmetrical diaryl selenides via cascade reaction of selenourea with aryl halides/boronic acids.

Selenourea is used as an effective selenium surrogate in the C-Se cross-coupling reaction catalyzed by copper oxide nanoparticles under ligand free conditions. This protocol has been utilized for the synthesis of a variety of symmetrical diaryl selenides in good to excellent yields from the readily available aryl halides/boronic acids.