- Regioselective iodination of chlorinated aromatic compounds using silver salts
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The iodination of chlorinated aromatic compounds using Ag 2SO4/I2, AgSbF6/I2, AgBF4/I2, and AgPF6/I2 offers access to iodoarenes that are valuable intermediates in organic synthesis. Specifically, iodination of phenols, anisoles, and anilines with a 3,5-dichloro substitution pattern preferentially yielded the ortho, para, and para iodinated product, respectively. In the case of chlorobenzene and 3-chlorotoluene, AgSbF6/I2, AgBF4/I2, and AgPF 6/I2, but not Ag2SO4/I2, selectively introduced the iodine in para position to the chlorine substituent.
- Joshi, Sudhir N.,Vyas, Sandhya M.,Wu, Huimin,Duffel, Michael W.,Parkin, Sean,Lehmler, Hans-Joachim
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experimental part
p. 7461 - 7469
(2011/10/10)
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- STOICHIOMETRIC AND CATALYTIC OXIDATIVE IODINATION OF AROMATIC COMPOUNDS IN THE PRESENCE OF NITROGEN-CONTAINING OXIDIZING AGENTS IN AQUEOUS TRIFLUOROACETIC ACID
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The conditions for oxidative monoiodination of benzene, halogenobenzenes, toluene, halogenotoluenes, and p-toluic acid in solvents based on trifluoroacetic acid were studied.Yields of the respective iodoarenes close to quantitative were obtained in systems containing 10-20 vol. percent of water in the solvent with equimolar amounts of alkali-metal metal iodides in relation to the substrate in the presence of stoichiometric (under anaerobic conditions) or catalytic (in the presence of oxygen or air) amounts of alkali-metal nitrates.The analogous reactions with nitrites can only be conducted under aerobic conditions.These iodinating systems are compared with systems based on acetic acid containing iodine and mixtures of sulfuric and nitric acids.The conditions for the iodination of toluene and for the transformations of the obtained iodotoluenes in the presence of nitrogen-containing oxidizing agents in trifluoroacetic acid solutions were studied in detail.It was shown that p-iodotoluene undergoes ipso-nitrodeiodination to a significant degree under these conditions.It is supposed that the iodinating agent in the investigated systems is trifluoroacetyl hypoiodite.Data on the assignment of the PMR spectra of the synthesized isomeric nitroiodotoluenes and chloroiodotoluenes by a simple additive method are given.
- Makhon'kov, D. I.,Cheprakov, A. V.,Beletskaya, I. P.
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p. 2029 - 2035
(2007/10/02)
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