PENTAFLUOROPHENYLCOPPER TETRAMER

PENTAFLUOROPHENYLCOPPER TETRAMER, A REAGENT FOR SYNTHESIS OF FLUORINATED AROMATIC COMPOUNDS... 

The pentafluorophenylcopper tetramer is usually analytically pure as isolated and melts at 200° with decomposition. If any significant decomposition occurs during the final drying, the product can be purified by dissolution in ether, filtration to remove copper metal, and precipitation by addition of hexane. It can also be recrystallized from benzene. When kept in a sealed container under nitrogen at room temperature, pentafluorophenyl copper tetramer appears to be stable for reasonable periods. It can be stored indefinitely at -78° under an atmosphere of carbon dioxide. 

HPentafluorophenyOadamantane, 59, 130 (Pentafluorophenyl)benzene, 59, 127 Pentafluorophenylcopper, 59, 124 Pentfluorophenylcopper complexes, 59, 127 PENTAFLUOROPHENYLCOPPER TETRAMER, 59,122 2-(Pentafluorophenyl)ethylamine hydrochloride, 57, 82... 

A. (Pentafluorophenyl)benzene. A 100-ml., round-bottomed flask equipped with a magnetic stirring bar and a reflux condenser bearing a nitrogen inlet is flushed with nitrogen. The flask is charged with a solution of 2.40 g. (0.0026 mole) of pentafluorophenylcopper tetramer in 25 ml. of benzene, and 2.12 g. 

Pentafluorophenylcopper tetramer Copper, tetrakis(pentafluoro-phenyl)tetra- (8,9) (34077-61-7)... 

Trifluoromethyl)phenylcopper was found to be an octamer by consideration of the kinetics of its decomposition, and by cryoscopy and vapor pressure osmometry in benzene solution 36). Its F NMR spectrum in ether at room temperature is a sharp singlet. Consequently, the suggested structure is a central copper cube with equivalent bridging benzotri-fluoride groups. The initial decomposition product, Cu8( n-CF3CgH4)e, is considered to be a Cu(0)—Cu(I) octanuclear cluster compound 36). For the octameric m-(trifluoromethyl)phenylcopper, the tetrameric ortho isomer, and pentafluorophenylcopper tetramer, the F NMR spectra were found to vary with temperature. The changes are not considered to involve important structural alterations, but only variations in solvent complexes and rotamer populations 32, 37). The spectra also... 

Pentafluorophenylcopper tetramer is reported to form complexes with the 7T-bases 2-butyne and 1,5-cyclooctadiene (52). 

Perfluoroalkylcopper and perfluoroarylcopper compounds are noticeably more thermally stable than the corresponding alkyl and aryl compounds. Solutions of perfluoroalkylcopper compounds in DMSO or DMF are stable up to at least 120°C 200), whereas ether suspensions of alkylcopper compounds decompose at 0°C or below. Similarly, pure pentafluorophenylcopper tetramer decomposes at 210°C-220°C, and a sample has been kept in a Dry Ice chest for 5 years 32). However pure phenylcopper can be kept for no more than a few days, even under nitrogen 73). Solutions of pentafluorophenylcopper reagents containing metal halides in THF have been refluxed for 5 days or more without decomposition (97, 144). Other stable perhaloarylcopper reagents are those in which the aryl moiety is perfluoro(p-phenoxyphenyl) (96), pentachlorophenyl, and 2,3,5,6-tetrachloropyridyl 144), none of which... 

Copper compounds are catalysts for the Michael addition reaction (249), olefin dimerizations (245, 248), the polymerization of propylene sulfide (142), and the preparation of straight-chain poly phenol ethers by oxidation of 2,6-dimethylphenol in the presence of ethyl- or phenyl-copper (209a). Pentafluorophenylcopper tetramer is an intriguing catalyst for the rearrangement of highly strained polycyclic molecules (116). The copper compound promotes the cleavage of different bonds in 1,2,2-tri-methylbicyclo[1.1.0]butane compared to ruthenium or rhodium complexes. Methylcopper also catalyzes the decomposition of tetramethyllead in alcohol solution (78, 81). 

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