Xu Jianjun, Burton Donald J
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA.
J Org Chem. 2006 May 12;71(10):3743-7. doi: 10.1021/jo060068i.
A highly stereoselective method to prepare both (E)- and (Z)-alpha-fluorostilbenes is described. 1-Bromo-1-fluoroalkenes (E/Z approximately 1:1), a readily available starting material, isomerizes to high E/Z ratios by storage at -20 degrees C or by photolysis at 254 nm. Stille coupling between these high E/Z 1-bromo-1-fluoroalkenes and aryl stannanes gave (Z)-alpha-fluorostilbenes in high stereoselectivity. (Z)-1-Bromo-1-fluoroalkenes, which were kinetically separated from 1-bromo-1-fluoroalkenes (E/Z approximately 1:1), can participate in Suzuki coupling reactions to give (E)-alpha-fluorostilbenes stereoselectively.
描述了一种制备（E）-和（Z）-α-氟代芪的高度立体选择性方法。1-溴-1-氟代烯烃（E/Z约为1:1），一种容易获得的起始原料，通过在-20℃下储存或在254nm处光解异构化为高E/Z比。这些高E/Z的1-溴-1-氟代烯烃与芳基锡烷之间的Stille偶联以高立体选择性得到（Z）-α-氟代芪。从1-溴-1-氟代烯烃（E/Z约为1:1）中通过动力学分离得到的（Z）-1-溴-1-氟代烯烃可参与铃木偶联反应，以立体选择性地得到（E）-α-氟代芪。
