由不同硫含氧酸盐引发的氟烷基化内酯化反应

Polyfluoroalkylation Lactonization Initiated by Sulfur-oxy Acid Salts

以4-氯八氟碘代丁烷和4-戊烯酸生成含氟丁内酯的反应为模板,详细研究了不同硫含氧酸盐、溶剂和温度对反应的影响。实验结果表明:以二氧化硫脲、雕白粉、亚硫酸钠、亚硫酸氢钠、偏重亚硫酸钠等硫含氧酸盐为引发剂,4-氯八氟碘代丁烷和4-戊烯酸的氢氧化钠水溶液与乙腈或DMF为共溶剂,于20～55°C搅拌反应3～15h,后处理并通过柱层析得到含氟内酯产物。以二氧化硫脲为引发剂,乙腈为共溶剂(V(乙腈)∶V(水)=1∶1),在35°C下反应5h,得到的含氟内酯产率最高(84.3%)。在此条件下,其他含氟碘代烷与4-戊烯酸反应,得到相应的含氟内酯化合物,收率为72.7%～86.2%。

The polyfluoroalkylation lactonization of 4-pentenoic acid with 4-chlorododecafluorobutyl iodide initiated by several sulfur-oxy acid salts, such as thiourea dioxide, rongalite, sodium sulfite, sodium bisulfite and sodium disulfite, to give the correponding fluorine-containing lactones was intensively studied. The influence of temperature, time and cosolvent on the reaction was discussed. Results show that lactone is obtained after usual workup when the mixture of 4-pentenoic acid and 4-chlorodode-cafluorobutyliodide are stirred in the presence of different sulfur-oxy acid salts at 20-55°C for 3-15 h in aqueous acetonitrile (or DMF) solution. When the reaction was initiated by thiourea dioxide at 35°C for 5 h in aqueous acetonitrile solution the yield was the highest (84.3%). Polyfluoroalkylated lactones can be obtained in 72.7%-86.2% yields by reaction of 4-pentenoic acid and polyfluoroalkyl iodides under similar conditions.