621-32-9Relevant articles and documents
Iodine-catalyzed tandem oxidative aromatization for the synthesis of meta-substituted alkoxybenzenes
Jiang, Dahong,Jia, Xicheng,Zhang, Shuhua,Zhang, Zhihua,Li, Lei,Qiao, Yanhui
supporting information, (2021/06/12)
A rapid method for the synthesis of meta-substituted alkoxybenzenes is achieved by oxidation of cyclohexenones. This one-pot transformation is catalyzed by molecular iodine with DDQ as an oxidant in the presence of alcohols. Diverse cyclohexenones with aryl or alkyl substitutes are well tolerated to the mild oxidative conditions affording desired products in up to 92% yield. These oxidizing processes were applicable to the efficient synthesis of useful meta-substituted phenolic products which are difficult to obtain by traditional electrophilic substitutions.
Solvent-free Williamson synthesis: An efficient, simple, and convenient method for chemoselective etherification of phenols and bisphenols
Massah, Ahmad R.,Mosharafian, Masumeh,Momeni, Ahamad R.,Aliyan, Hamid,Naghash, H. Javaherian,Adibnejad, Mohamad
, p. 1807 - 1815 (2008/02/02)
Etherification of phenols with dimethyl- and diethylsulfates and benzyl chloride was performed efficiently in the presence of a suitable solid base, NaHCO3 or K2CO3, under solvent-free conditions. The reaction proceeded rapidly at low temperature, and the corresponding ethers were obtained with high purity and excellent yield. Selective etherification of electron-poor phenols in the presence of electron-rich ones and also selective mono-etherification of bisphenols are the noteworthy advantages of this method. This method is environmentally friendly. Copyright Taylor & Francis Group, LLC.
pH effects on ethanolysis of some arenediazonium ions: Evidence for homolytic dediazoniation proceeding through formation of transient diazo ethers
Pazo-Llorente, Roman,Bravo-Diaz, Carlos,Gonzalez-Romero, Elisa
, p. 3221 - 3226 (2007/10/03)
The effects of pH on the observed rate constants (kobsd.) and on the solvolytic dediazoniation product distributions of ethanolysis of 2-, 3-, and 4-methylbenzenediazonium ions (2MBD, 3MBD, and 4MBD, respectively) were determined by a combination of spectrophotometric (UV/Vis) and Chromatographic (HPLC) techniques. The variation of both kobsd. and product yields with pH follow S-shaped curves with inflection points at pH ≈ 3.6, depending on solvent composition. With increasing pH, kobsd. values increase by factors of up to about 4 (2MBD), about 3 (3MBD), and about 50 (4MBD) with respect to the kobsd. values at low pH. HPLC analyses of the reaction mixtures show that only heterolytic products are obtained at low pH, indicating that solvolytic dediazoniation takes place through an ionic mechanism, but an increase in pH favors homolytic dediazoniation, with quantitative conversion into the reduction product toluene being obtained at pH ≥ 6 (4MBD), indicating that a turnover from the heterolytic to the homolytic mechanisms is taking place under experimental conditions under which insignificant amounts of EtO- or OH- should be present in solution. The obtained S-shaped profiles suggest that the initiation process of the homolytic pathway is the result of the formation of a highly unstable transient diazo ether complex and not by direct electron transfer from the solvent (EtOH) to the arenediazonium ions as is currently believed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
