Convenient Preparation of Deuterated Fluoroolefins

摘要

The reduction of iodo-containing fluoroolefins with NaAlH4 in diglyme followd by hydrolysis with D2O provides a convenient preparative procedure to the corresponding deuterated fluoroolefin. Polyflourinated olefins generally react with complex metal hydrides either via nucleaophilic displacement of vinylic halogen by hydrogen or allylic displacement of fluorine through an SN2 type recation (1,2). Olefins that contain vinylic iodide, however, do not undergo nucleophilic substitution when reacted with LiAlH4 in ether. Instead, they form aluminum complexes, which are stable in solution. Evidence for this alternate mode of reaction was obtained from GLPC analysis of the reaction mixture before and after hydrolysis, measurement of the hydrogen gas evolved during the reaction, and an investigation of the amount of deuterated vs. protonated product obtained if hydrolysis of the reaction mixture was carried out with D2O.