- Method for making ethynylated aromatic compounds and a method for making nitronium trifluoromethanesulfonate
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A method is disclosed for making amino-substituted ethynylated biphenyl compounds, which includes selectively nitrating symmetrically substituted biphenyl compounds, reacting the resulting nitro-substituted aromatic compound with a copper acetylide to replace the iodo substituents with ethynyl groups, and then reacting the ethynylated, nitro-substituted aromatic compound with hydrogen in the gas phase to reduce the nitro groups to amino groups. The preferred nitrating agent is nitronium trifluoromethanesulfonate, made by reaction of anhydrous nitric acid with trifluoromethanesulfonic anhydride in an anhydrous solvent.
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- Anomaly in Palladium-Catalyzed Phenylethynylation of 2,2'-Dihalobiphenyls: Formation of Alkylidenefluorenes
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2,2'-Diiodobiphenyl and 5,5'-dinitro-2,2'-dihalobiphenyls underwent palladium-catalyzed phenylethynylation with 2 mol of phenylacetylene to yield 3-(fluoren-9-ylidene)-1,3-diphenylpropyne and 3-(3,6-dinitrofluoren-9-ylidene)-1,3-diphenylpropyne, respectively.These fluorenyl compounds exhibited well-defined splitting patterns for the fluorenyl ring protons in the 250-MHz proton NMR spectra.The structure of 3-(fluoren-9-ylidene)-1,3-diphenylpropyne was further confirmed by an independent synthesis via the thermolysis of diethyl 3-(fluoren-9-ylidene)-1,3-diphenylpropen-1-yl phosphate.The mechanistic importance of the complex iodo(fluoren-9-ylidenebenzyl)bis(triphenylphosphine)palladium(II) in the catalytic cycle was established on the basis of its reaction with phenylacetylene to give 3-(fluoren-9-ylidene)-1,3-diphenylpropyne.
- Dougherty, T. Kirk,Lau, Kreisler S. Y.,Hedberg, Frederick L.
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p. 5273 - 5280
(2007/10/02)
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- Phenylethynyl substituted aromatic diamines
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As new compositions of matter, 2,2'-bis(phenylethynyl)-4,4'-diaminobiphenyl and 2,2'-bis(phenylethynyl)-5,5'-diaminobiphenyl. The compounds are useful as monomers suitable for the preparation of thermally stable polymer systems such as polyimides, polyami
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