Hydroselenation of Terminal Alkynes Catalyzed by Cesium Hydroxide: Highly Stereo- and Regio-selective Synthesis of (E)-1-Arylselenoalkenes

Abstract

In the presence of catalytic amount of cesium hydroxide, the hydroselenation of terminal alkynes occurred in N,N-dimethylformamide (DMF) at room temperature under nitrogen atmosphere to afford (E)-1-organseleno-1-alkene in high yields. The reaction mechanism is that selenols reacted with cesium hydroxide to give cesium selenides, which underwent nucleophilic addition to the alkynes to form selenium vinylic anion, hydrolyzed to give product (E)-1-organoselenovinylene and catalyst cesium hydroxide. The method could provide a new and expedient way for the hydroselenation of unactivated alkynes.