Synthesis of α,β-Unsaturated Phosphine Sulfides

α,β-Unsaturated phosphine sulfides may exhibit different reactivity from α,β-unsaturated phosphine oxides toward nucleophilic addition and thus may find new applications in copper(I)-catalyzed asymmetric reactions. Herein, various α,β-unsaturated phosphine sulfides were prepared in moderate to excellent yields from the parent α,β-unsaturated phosphine oxides with Lawesson’s reagent. The reaction enjoys a broad substrate scope and tolerates a variety of functional groups.