Preparation of fluorinated radicals and their applications to synthetic reactions

Free radical reactions leading to carbon-carbon bond formation have emerged as a powerful tool in organic synthesis. We have been investigating the fluoroalkylation of organic molecules using radical species. The main subjects in our study are how to generate fluorinated alkyl radicals, and how to control the radical reaction. The photochemical reaction of fluoroalkyl iodide with ditin was found to be a good method for the generation of fluorinated radicals, and the generated fluorinated radicals could be effectively introduced into olefinic compounds. By the use of this method, efficient synthesis of fullerene dimers containing a fluoroalkyl group and oxygenative fluoroalkylation of styrenes were accomplished. One-electron reduction of fluorinated alkyl halides using SmI2 or Na2S2O4 was also investigated. Simultaneous introduction of fluorinated radical with other radical species such as oxygen, or fluorinated radical with electrophiles into olefinic compounds could be performed by using fluorinated alkyl halides with one-electron reducing reagent.