氢氧化铯促进下硒、端炔及卤代烃反应合成炔硒醚

DMF作溶剂, 4Å分子筛存在下, 将端炔、CsOH、硒粉在室温搅拌2 h, 然后加入溴代烃或二芳基碘盐, 在室温下搅拌20 h, 得炔硒醚, 收率约60%. 反应机理为端炔与氢氧化铯作用形成炔化铯, 然后元素硒进行C—Cs键插入形成炔硒化铯, 炔硒化铯对溴代烃或二芳基碘盐进行亲核取代得到相应的炔硒醚

Cesium Hydroxide Promoted Reaction of Element Selenium with Terminal Alkynes and Alkyl Halides to Synthesize Acetylenic Selenides

In the presence of 4Å MS, a mixture of terminal acetylene, cesium hydroxide and element selenium in DMF was stirred under N2 atomsphere at room temperature for 2 h, then alkyl bromides or diaryliodonium salts were added to the mixture and the resulting mixture was stirred at room temperature for 20 h to give acetylenic selenides in about 60% yields. The mechanism involved the reaction of terminal acetylene with cesium hydroxide to form the cesium alkynide, then selenium inserted into C—Cs bond and gave the cesium alkynylselenoate, which underwent nucleophilic substitution with alkyl bromides or diaryliodonium salts to give the corresponding acetylenic selenides.