A general method for nearly reduction-free dehalogenations in a fluorinated biphasic system

We have studied the dehalogenations of halofluorinated alkanes and fluorinated ethers, both linear and cyclic, as well as halofluorinated alkanes containing an aromatic moiety, to their corresponding unsaturated species in a biphase fluorinated/hydrogenated solvent system. actions in the biphase system lead to higher selectivities and better yields than those obtained performing the reaction in the traditional hydrogenated monophasic system. By this method, the concentrations of hydrogenated by-products of general formula R–CF2H or RCFHR’ are as low as 100 ppm. ovel biphasic system provides therefore a useful synthetic route to materials and chemicals for electronics, optical polymers, plasma etching, etc. which require a very high purity of all compounds involved.