文摘
2,2-Difluorovinyl p-toluenesulfonate, readily obtained from 2,2,2-trifluoroethanol, is treated with zirconocene equivalent “Cp2Zr” to generate the remarkably thermostable nonsubstituted 2,2-difluorovinylzirconocene, which in turn couples with aryliodides in the presence of palladium catalyst and zinc iodide to afford monosubstituted gem-difluoroolefins in high yields. The reaction proceeds via 2,2-difluorovinylzinc as confirmed by 19F-NMR measurement.