In the presence of catalytic amount of cesium hydroxide, under nitrogen atmosphere terminal alkynes reacted with diaryl disulfides at room temperature in commercial THF to give almost exclusive (Z)-1,2-diarylthio-1-alkene in good yields, but under air atmosphere the reaction gave a mixture of alkynyl sulfide and (Z)-1,2-diarylthio-1-alkene. But for the reaction of diarylditellurides with terminal alkynes, whether it was performed under nitrogen atmosphere or air atmosphere, it only gave alkynyl tellurides. However, the yields of the alkynyl tellurides obtained under nitrogen atmosphere is only 50% of yields obtained under air atmosphere. The reaction mechanism was discussed.

Key words: cesium hydroxide, diaryl disulfides, (Z)-1,2-bis-(arylthio)-1-alkene, diarylditellurides, alkynyl tellurides