- An overview on the progress and development on the palladium catalyzed direct cyanation
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Generation of the positive CN ion and the corresponding direct cyanation are both extremely important for cyanation of aromatic compounds. Hereby, we would like to report the simultaneous use of the new Pd nano-catalyst as well as the three types of the N-arylsulfonyl cyanamides (A, B and C) as potent reagents for the in situ generation of the positive CN ion for the direct cyanation of phenylboronic acids in acetonitrile at reflux conditions.
- Heydari, Somayyeh,Habibi, Davood,Reza Faraji, Ali,keypour, Hassan,Mahmoudabadi, Masoumeh
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- Effect of para substitution on dissociation of N-phenylbenzenesulfonamides
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The reaction of substituted anilines and benzenesulfonyl chlorides has been used to prepare 49 substituted N-phenylbenzenesulfonamides of general formula 4-X-C6H4SO2NHC6H4-Y- 4′. Their purity was checked by elemental analysis. The substituents X and Y include H, CH3, CH3O, Cl, Br, CN, and NO2. The dissociation constants of all compounds were determined by potentiometric titration in methanol, acetonitrile, N,N-dimethylformamide, and pyridine. The obtained dissociation constants, pKHA, were correlated with various sets of substituent constants. It was found that the effects of substituents X and Y on the dissociation are best described by using the Hammett equation with σp constants and the Yukawa-Tsuno equation with σp- and σp constants, respectively. This result confirms the direct conjugation of Y substituent with the reaction centre. The explained variability using the additive model was above 96% in all the solvents used. The data also provided information about the transmission effect of the SO2 group. The average dissociation constants were further processed by the latent variables methods, principal components and conjugated deviations analyses.
- Mansfeld, Martin,Parik, Patrik,Ludwig, Miroslav
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p. 1479 - 1490
(2007/10/03)
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