Synthesis and Reactions of Perfluoroaliphatic Grignard Compounds

摘要

Perfluoroaliphatic mono- and di-Grignard reagents (RfMgX, XMgR'(f)MgX) have conveniently synthesized through a metal-halogen exchange reaction. Excellent yields (90-100%) of the mono- or di-Grignard reagent have been obtained by this method. The degree of exchange is subject to a number of experimental parameters, e.g., the solvent (tetrahydrofuran vs. diethyl ether), a type of displaced halide (R(f)X; Br vs. I), an organomagnesium exchange reagent (RMgX; R = CH3-, C2H5-, CH2=CHCH2-, C6H5-), and stoichiometry. The stability of the perfluoroaliphatic magnesium is a function of temperature and solvent. The products of thermal decomposition, however, are a function of type of perfluoroorganomagnesium reagent and solvent. These organomagnesium reagents have sufficient thermal stability at low temperatures (-78C) to be useful as intermediates for the synthesis of a variety of compounds. (Modified author abstract)