26449-33-2Relevant articles and documents
Highly selective aromatic alkylation of phenol and anisole by using recyclable bronsted acidic ionic liquid systems
Titze-Frech, Karin,Ignatiev, Nikolai,Uerdingen, Marc,Schulz, Peter Steffen,Wasserscheid, Peter
, p. 6961 - 6966 (2013)
A highly efficient ionic liquid catalyst system for selective alkylation of phenol and anisole with alkenes is described. By using Bronsted acidic triflate ionic liquids containing the SO3H group attached to the cation, it was possible to recycle the catalyst and reuse it after a simple workup procedure. Moreover, selectivity towards the monoalkylated products was improved to 93 % by using a biphasic system. A sulfonic acid functionalized ionic liquid is used as catalyst in the hexylation of phenol and anisol, enabling very high product selectivities, simple product isolation and effective catalyst recycling. The observed selectivity boost is mainly due to differential solubility effects of the liquid-liquid biphasic reaction system established by the ionic liquid catalyst. Copyright
Acidity effect in the regiochemical control of the alkylation of phenol with alkenes
Sartori, Giovanni,Bigi, Franca,Maggi, Raimondo,Arienti, Attilio
, p. 257 - 260 (2007/10/03)
Treatment of 1:1 mixtures of phenol and linear alkenes in the presence of an acidic promoter in CHCl3 at room temperature results in ortho-regioselective monoalkylation producing sec-alkylphenols in 48-60% yield. In similar reactions, branched alkenes lead exclusively to the corresponding para-tert-alkylphenols in 80-85% yield. Addition of increasing amounts of potassium phenolate to the reacting system reduces the protic acidity and promotes ortho-regioselective tert-alkylation. These results are tentatively explained in terms of competition of 'H-bond-template' and 'charge-controlled' mechanisms.
Equilibria for the isomerization of (secondary-alkyl)phenols and cyclohexylphenols
Nesterova, T. N.,Pimerzin, A. A.,Rozhnov, A. M.,Karlina, T. N.
, p. 385 - 396 (2007/10/02)
Equilibria of a series of isomerizations and trans-alkylations of alkylphenols have been investigated in the liquid phase over a wide range of temperatures.Equilibria of isomerizations connected with the displacement of a substituent on a benzene nucleus were studied for secondary-butyl, -amyl, -hexyl, and cyclohexyl-phenols, and di-(secondary-butyl)phenols.Equilibria of positional isomerization connected with the displacement of an oxyphenyl radical in an alkyl chain were investigated for oxyphenyl-pentanes, -hexanes, -octanes, and -decanes.Trans-alkylation was investigated for di- and tri-(secondary-butyl)phenols.Values of ΔrH0m and ΔrS0m were found for all investigated reactions.An analysis was made of the thermodynamic quantities for the reactions.Enthalpies of formation of isopropylphenols (IPP) in the gaseous state were calculated.The values of ΔfH0m/(kJ * mol-1) were found at 298.15 K: o-IPP, -(175.3 +/- 2.4); p-IPP, -(175.3 +/- 2.4); m-IPP, -(175.3 +/-2.4); 2,4-di-IPP, -(254.1 +/- 2.8); 2,5-di-IPP, -(254.1 +/- 2.8); 2,6-di-IPP, -(254.1 +/- 2.8); 3,5-di-IPP, -(254.1 +/- 2.8); 2,4,6-tri-IPP, -(333.0 +/- 3.1).
