Perfluorophenyl bromide

As is general for organosilver compounds, perfluorophenylsilver is considerably more stable than phenylsilver.55 The first example of a perfluoroarylsilver compound was reported by Miller and Sun in 1970.49 Reaction of perfluorophenyllithium with silver trifluoroacetate, or of perfluorophenyl bromide with perfluoroisopropylsilver, gave perfluorophenylsilver as colorless crystals (Scheme 1.17). The compound was found to be stable up to 150°C, at which temperature it slowly dimerized to give perfluorobiphenyl and metallic silver. Since this initial report a number of syntheses of perfluorophenylsilver from perfluorophenyllithium followed.56,57... 

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). " ... 

The reaction of trimethyl(perfluorophenyl)stannane with germanium(l V) chloride also proceeds smoothly, but the yield of trichloro(perfluorophenyl)germane (II. X = Cl) is rather low. Germanium(lV) bromide completely reacts with trimethyl(perfluorophcnyl)stannane over 22 hours. Apart from bromotrimethyltin. the reaction produces dibromodimethyltin. which makes it diflficult to isolate the target product. The reaction of germanium(IV) chloride with trimethyl(perlluorophenyl)silane does not proceed at a high temperature (240 C, 46 h), or in acetonitrile in the presence of cesium fluoride (50 C. 7 h). 

Perfluorophenyl)copper exhibits high reactivity towards organic substrates. and reacts with fluorinated or nonfluorinated aryl iodides (e.g., formation of 5), fluorinated vinyl iodides, al-kynyl bromides and iodides, allyl halides, alkanoyl halides, and iodomethane to afford the corresponding coupled products in good yields. (Perfluorophenyl)copper readily undergoes addition in a syn fashion to perfluorobut-2-yne to form a perfluorovinylcoppcr reagent 6, which can be quenched by electrophiles (e.g. formation of 7). Recall that (per-fluorophcnyl)coppcr reacts with (trifluoromethyl)copper to form (perfluorophenethyl)copper (Section 2.1.1.3.3.). 

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