C-Si bond formation and fluoro(2.2)cylophane synthesis by C-F bond activation

氟环烷已被认为是一种有前途的热稳定绝缘体聚合物单体，可用于大规模半导体制造。为了开发一种实用的环烷合成方法，对镁促进的C-F键活化进行了广泛的研究。在DMF中，在三甲基硅烷存在的情况下，双氟甲基苯与镁的反应是一种可行的方案。该反应以50-60%的收率得到了所需的三甲基硅基化苄基化合物。氟催化脱硅脱氟，通过醌二甲烷以53%的收率得到所需的环烷。从双三氟甲基苯的可得性来看，本方法将与基于锌金属促进脱氯制备的Dolbier方法相竞争。

Fluorocyclophanes have been recognized as a promising monomer for thermally stable insulator polymer useful for large scale semiconductor manufacturing. In order to develop a practical synthetic method for the cyclophane, Mg-promoted C-F bond activtion has been extensively studied. And one of the protocol for the purpose has been found which consists of reaction of bistrifluoromethyl benzene wirh magnesium in the presence of trimethylsilane in DMF. The reaction provided the desired trimethylsilylated benzyl compound in 50-60% yields. Fluroride-catalyzed desilylated defluorination gave the desired cyclophane via quinodimethane in 53% yield. The present method will be competitive to the Dolbier method based on Zn-metal promoted dechlorinative preparation from the point of availability of bistrifluoromethylbenzene.