Mercury bromide, reaction with Grignard reagent

Trimethyl(perfluorophenyl)silanc (1) is synthesized by the reaction of the Grignard reagent obtained from bromopentafluorobenzene and magnesium, with chlorotrimethylsilane in diethyl ether (90% yield), or by irradiation of a mixture of bis(trimethylsilyl)mercury and perfluoro-phenylmercury bromide (40% yield). " ... 

Decarboxylation of an aliphatic acid to the hydrocarbon is best effected by the so-called salt degradation method. That method is to treat the silver or mercury salt of, preferably, an aliphatic or alicyclic carboxylic acid with bromine in an inert solvent a halogenated hydrocarbon is then formed, together with carbon dioxide and the metal bromide, usually in an exothermic reaction, and the bromine can then usually be readily removed either cata-lytically or by means of a Grignard reagent (the Hunsdiecker reaction) ... 

---