Treatment of readily prepared (Z)-6-benzyloxy-1,1,1,2-tetrafluoro-6-methyl-2-hepten-4-yne with 1.5 equiv of LHMDS in −78 °C for 1 h gave the corresponding trifluoromethylated diyne in an excellent yield. This diyne was found to be a good substrate for the carbocupration with various higher-ordered cyanocuprates to give the corresponding vinylcuprates in a highly regio- and stereoselective manner. The in situ generated vinylcuprates could react very smoothly with an excess amount of iodine, the vinyl iodides being obtained in high yields. Thus-obtained iodides underwent a very smooth Sonogashira cross-coupling reaction to afford various trans-enediynes in high yields.
在-78°C条件下,将预先制备的(Z)-6-苄氧基-1,1,1,2-四氟-6-甲基-2-庚炔-4-炔与1.5当量的LHMDS反应1小时,得到相应的三氟甲基化二炔,收率极高。发现该二炔是一种良好的底物,可与各种高阶氰基铜盐发生烷基化反应,以高度区域和立体选择性的方式生成相应的乙烯基铜盐。原位生成的乙烯基铜盐可以与过量碘反应非常顺利,乙烯基碘化物收率很高。因此获得的碘化物经历了非常顺利的Sonogashira交叉偶联反应,以高收率得到各种反-二炔。