Phase Transfer Catalytic System Research Articles

Synthesis of phenoxypyridines under phase transfer catalysis conditions

Reactions of halopyridines with alkali metal phenoxides in a two phase liquid-solid catalytic system, rather than in a liquid-liquid phase transfer catalytic system, make it possible to prepare 2-, 3-, and 4-phenoxypyridines from unactivated bromo- or chloropyridines and 2-chloropicolines. In polyhalogenated pyridines only α- and γ-halogen atoms undergo substitution. 7, 8-Dibromo-6-azaphenoxane has been prepared by the reaction of 2,3,5,6-tetrabromopyridine with the dipotassium salt of pyrocatechol.

Kinetic determination of selectivity constants of anion extraction in phase-transfer catalytic systems

A kinetic method has been developed to measure selectivity constants of pairs of anions in phase-transfer catalytic systems. The method is based on the study of the poisoning effect produced by the presence of catalytic amounts of different salts in the kinetic behaviour of the phase-transfer-catalysed isomerization of 4-allylanisole to 4-methoxy-β-methylstyrene in basic medium. The kinetic profiles experimentally obtained for this reaction are numerically analysed and Ksel values for different anions are subsequently derived. Particular attention is given to alkoxide anions, formed in situ by contact of alcohols with concentrated NaOH. A selectivity constant parameter that includes the acidity of the alcohols is defined.

Synthesis of diethylamides of ?-diethylaminocarboxylic acids using ?-trichloromethylcarbinols and their acetates under phase-transfer catalysis conditions

Trichloromethyicarbinols and their acetates react with diethylamine under phase-transfer catalysis conditions to give diethylamides of α-diethylaminocarboxylic acids. The same products are formed in the reaction of aldehyde acylals with chloroform and diethylamine in the 50% aqueous NaOH-BTEAC phase-transfer catalytic system.

Sodium hypochlorite as oxidant in phase transfer catalytic systems: Part I. Oxidation of aromatic aldehydes

Aromatic aldehydes were oxidized to carboxylic acids in high yields and selectivity under mild conditions. The reactions were performed using aqueous sodium hypochlorite as oxidant in a liquid-liquid phase transfer catalytic system using quaternary ammonium salts as catalysts. The reaction was strongly pH-dependent, with maximum reaction rates at pH 9–11. Similarly, extraction of the hypochlorite ion was maximal at these pHs. The maxima are attributed to coextraction of hypochlorous acid together with the hypochlorite anion into the organic phase, the former significantly increasing the reaction rate.

Sodium hypochlorite as oxidant in phase transfer catalytic systems: Part II. Oxidation of aromatic alcohols

Benzyl alcohol was oxidized by aqueous sodium hypochlorite in a phase transfer catalysis reaction catalyzed by quaternary ammonium salts. Two products were obtained, benzaldehyde and benzyl benzoate. The concentration of the organic phase and the pH of the aqueous phase affected the product distribution: a dilute organic phase and low pH favored benzaldehyde as a product, whereas a concentrated organic phase and high pH favored benzyl benzoate as a product.

Reactions of trinitrotoluenes with sodium borohydride in a phase transfer catalytic system

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of trinitrotoluenes with sodium borohydride in a phase transfer catalytic systemYoshiyuki Okamoto and S. T. AttarwalaCite this: J. Org. Chem. 1979, 44, 18, 3269–3271Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://doi.org/10.1021/jo01332a040RIGHTS & PERMISSIONSArticle Views86Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (433 KB) Get e-Alerts Get e-Alerts