Copper-catalyzed chalcogenation of aryl iodides via reduction of chalcogen elements by aluminum or magnesium

Aluminum-induced copper-catalyzed coupling of aryl iodides with selenium or sulfur element could afford the corresponding diaryl selenides or sulfides in good yields. When magnesium chloride as an additive was employed, diaryl monoselenides and monosulfides were selectively obtained. On the contrary, the use of sodium carbonate produced diaryl diselenides and disulfides. The preparation of diaryl diselenides was necessary for magnesium as a reductant. Regrettably, tellurium was very low reactivity.