Chemoselective synthesis of first representatives of bis(diorganothiophosphinyl)selenides, (R2P = S)2Se, from secondary phosphine sulfides and elemental selenium

First bis(diorganothiophosphinyl)selenides, (R2P = S)2Se, have been synthesized in 74–86% yield by the chemoselective interaction of secondary phosphine sulfides with elemental selenium (1:1 molar ratio, 100 °C, 3 h, 1,4-dioxane); the alternative bis(diorganoselenophosphinyl)sulfides, (R2P = Se)2S, are not formed under these conditions.