Facile Synthesis of β,β-Difluorostyrenes via the Negishi Coupling of Thermally Stable 2,2-Difluorovinyl Zinc–TMEDA Complex
作者:Takeshi Fujita、Tomohiro Ichitsuka、Kohei Fuchibe、Junji Ichikawa
DOI:10.1246/cl.2011.986
日期:2011.9.5
2,2-Difluorovinylzinc chloride–TMEDA complex, readily prepared from 1,1-difluoroethylene, undergoes the palladium-catalyzed coupling reaction with aryl halides to afford β,β-difluorostyrenes in high yield. This reaction not only proceeds smoothly with sterically hindered triflates and halides including chlorides, but also exhibits excellent chemoselectivities for multi-halogenated substrates. The intermediary TMEDA complex was found to be thermally stable and storable.
2,2-二氟乙烯锌氯–TMEDA复合物可通过1,1-二氟乙烯方便制备,能够与芳基卤化物进行钯催化的偶联反应,生成β,β-二氟苯乙烯,并具有高产率。该反应不仅能够顺利进行,适用于空间位阻较大的三氟甲基和卤化物(包括氯化物),而且对多卤素化底物表现出优异的化学选择性。中间体TMEDA复合物被发现具有热稳定性和可储存性。