Bromination Of Phenols Research Articles

A Controlled and Selective Bromination of Phenols by Benzyltriphenylphosphonium Tribromide.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A Controlled and Selective Bromination of Phenols by Benzyltriphenylphosphonium Tribromide

Reactions of phenols with benzyltriphenylphosphonium tribromide in dichloromethane–methanol mixture (2:1) gave mono, di and tri brominated phenols at room temperature with high selectivity and good yields.

Liquid phase bromination of phenols using potassium bromide and hydrogen peroxide over zeolites

An efficient, simple, mild and regioselective method for oxybromination of phenols catalyzed by CrZSM-5(30) is reported. The electrophilic substitution of bromine generated in situ from KBr as a bromine source and hydrogen peroxide as an oxidant.

Transition Metal-Catalyzed Oxidations. 11.Para-selective chlorination and bromination of phenols with tert-butyl hydroperoxide and TiX(OiPr)3

Mononuclear phenols 1–4 are chlorinated or brominated with high para-selectivity and in good yields to the halides 5–11 with the TiXn(OiPr)m/TBHP system (X = Cl or Br

A Process Scheme Involving Transalkylation Reactions To Prepare o-Bromophenol from Phenol

The bromination of phenol to o-bromophenol was carried out by protecting the para position with a tert-butyl group. The latter group was subsequently transferred to toluene using aluminum chloride as a catalyst. The resulting mixture of p- and m-tert-butyltoluene could be converted back to p-tert-butylphenol by transalkylation of the former with phenol in the presence of Engelhard, F-24. Thus, a process scheme based on transalkylation reactions as the intermediate steps has been proposed to synthesize o-bromophenol from phenol via p-tert-butylphenol. The effect of reaction parameters on overall conversion to and selectivity with respect to the desired product was studied for the transalkylation reactions involved in the process.

An Unusual Dehalogenating Peroxidase from the Marine Terebellid Polychaete Amphitrite ornata

The terebellid polychaete Amphitrite ornata produces no detectable volatile halogenated secondary metabolites, but frequently inhabits coastal marine sediments heavily contaminated with anthropogenic or biogenic haloaromatic compounds. This animal contains high levels of two very unusual enzymes, dehalogenating peroxidases. We have purified and partially characterized one of these dehaloperoxidases, DHP I. DHP I is a heme enzyme (Mr = 30,790) composed of two identical subunits (Mr = 15,529) and is very rich in the amino acids aspartic acid (+ asparagine) and glutamic acid (+ glutamine). The enzyme converts trihalogenated phenols, such as 2,4,6-tribromophenol, into dihalogenated quinones. The optimum pH for this reaction is 5.0. DHP I is also active against di- and monohalogenated phenols and will oxidize bromo-, chloro-, and fluorophenols. We have identified similar dehaloperoxidase activities in other infaunal polychaetes, including halometabolite-producing species.

Bromination of phenols using an algal bromoperoxidase

A crude acetone powder preparation from the red alga Corallina vancouveriensis has been found to serve as a convenient source of bromoperoxidase. This acetone powder (CVAP) catalyses the bromination of phenols in the presence of H 2O 2 and bromide. Conversion of substrate to product(s) is usually rapid and in high yield. The enzyme in the form of CVAP exhibits significantly greater stability than either the cell-free extract or purified bromoperoxidase. CVAP may be useful as a general source of bromoperoxidase and may extend the utility of this enzyme as a chemoenzymatic reagent.

Kinetics and Mechanism of Bromination of Phenol and Substituted Phenols by N-Bromobenzamide in Aquo-acetic Acid Medium

Kinetics and Mechanism of Bromination of Phenol and Substituted Phenols by N-Bromobenzamide in Aquo-acetic Acid Medium

Kinetics and Mechanism of Bromination of Phenol and Substituted Phenols by N-Bromobenzamide in Aquo-acetic Acid Medium

Kinetics and Mechanism of Bromination of Phenol and Substituted Phenols by N-Bromobenzamide in Aquo-acetic Acid Medium

ChemInform Abstract: The Bromination of Phenols is Simple. Or is It?

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Role of structure, medium and pathway in electrophilic aromatic substitutions. Part 3. Influence of isotope and solvent effects on electron release from phenolic O–H σ-bonds

The rate of molecular bromination of phenol at 25 °C in CH3CO21H as solvent exceeds the rate of the corresponding reaction in CH3CO22H by a factor of 1.5. Correction for substrate–solvent interaction brings the rate ratio to ca. 4.5, further confirmed by competitive bromination in the two media. A solvent isotope effect of this magnitude is indicative of substantial contribution to electrophilic reactivity from phenolic O–H σ-bonds.

Kinetics and mechanism of the bromination of phenols in aqueous solution. Evidence of general base catalysis of bromine attack

The reactions of bromine with phenol, 4-bromophenol, and 4-methylphenol (p-cresol) in aqueous solution are catalyzed by carboxylate anions, confirming the suggestions of earlier work. The results are consistent with deprotonation of the phenol hydroxyl group by a general base occurring at more or less the same time as electrophilic attack by molecular bromine. Possible origins of the general base catalysis are discussed. Combined with earlier results, the present findings suggest that a protonated cyclohexadienone is not a mandatory intermediate in phenol bromination; it can be avoided in both the formation of and enolization of the cyclohexadienone intermediate by general catalysis. Keywords: bromination, phenol, mechanism, catalysis, kinetics.

ChemInform Abstract: Regioselective Bromination in the Aromatic Series. Part 1. Monobromination of the para Position of Phenols and Aromatic Amines by Tetrabutylammonium Tribromide.

AbstractA mechanism involving electrophilic substitution by the tribromide anion Br3‐ is suggested to account for the regioselective bromination of phenols, e.g. (I), and amines such as (IX).

ChemInform Abstract: Kinetics and Mechanism of the Bromination of Phenols and Phenoxide Ions in Aqueous Solution. Diffusion‐Controlled Rates.

ChemInformVolume 20, Issue 26 Preparative Organic Chemistry ChemInform Abstract: Kinetics and Mechanism of the Bromination of Phenols and Phenoxide Ions in Aqueous Solution. Diffusion-Controlled Rates. O. S. TEE, O. S. TEE Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorM. PAVENTI, M. PAVENTI Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorJ. M. BENNETT, J. M. BENNETT Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this author O. S. TEE, O. S. TEE Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorM. PAVENTI, M. PAVENTI Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorJ. M. BENNETT, J. M. BENNETT Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this author First published: June 27, 1989 https://doi.org/10.1002/chin.198926105Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume20, Issue26June 27, 1989 RelatedInformation

The sequential bromination of phenols

L'enthalpie standard de reaction et de formation lors de la bromination de quatre phenols et de l'acide hydroxy-2 benzoique sont determinees par calorimetrique

Kinetics and mechanism of the bromination of phenols and phenoxide ions in aqueous solution. Diffusion-controlled rates

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanism of the bromination of phenols and phenoxide ions in aqueous solution. Diffusion-controlled ratesOswald S. Tee, Martino Paventi, and Janice M. BennettCite this: J. Am. Chem. Soc. 1989, 111, 6, 2233–2240Publication Date (Print):March 1, 1989Publication History Published online1 May 2002Published inissue 1 March 1989https://doi.org/10.1021/ja00188a044RIGHTS & PERMISSIONSArticle Views989Altmetric-Citations34LEARN 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 (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

ChemInform Abstract: Catalysis of the Bromination of Phenols (I) and Phenoxide Ions (II) in Aqueous Solution by α‐Cyclodextrin

ChemInformVolume 19, Issue 15 Preparative Organic Chemistry ChemInform Abstract: Catalysis of the Bromination of Phenols (I) and Phenoxide Ions (II) in Aqueous Solution by α-Cyclodextrin O. S. TEE, O. S. TEE Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorJ. M. BENNETT, J. M. BENNETT Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this author O. S. TEE, O. S. TEE Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this authorJ. M. BENNETT, J. M. BENNETT Dep. Chem., Concordia Univ., Montreal, Que., Can. H3G 1M8Search for more papers by this author First published: April 12, 1988 https://doi.org/10.1002/chin.198815116Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue15April 12, 1988 RelatedInformation

Catalysis of the bromination of phenols and phenoxide ions in aqueous solution by .alpha.-cyclodextrin

Catalysis of the bromination of phenols and phenoxide ions in aqueous solution by .alpha.-cyclodextrin

Oxybromination catalysed by the heteropolyanion compound H5PMo10V2O40 in an organic medium: selective para-bromination of phenol

Selective bromination of phenol and its derivatives and the bromination of ketones and alkenes have been achieved by oxybromination at ambient conditions catalysed by the mixed addenda heteropolyanion compound H5PMo10V2O40, which is dissolved in nonpolar chlorohydrocarbon solvent by complexation with tetraglyme.

ChemInform Abstract: Bromination of Phenols by Use of Benzyltrimethylammonium Tribromide.

ChemInformVolume 18, Issue 47 Preparative Organic Chemistry ChemInform Abstract: Bromination of Phenols by Use of Benzyltrimethylammonium Tribromide. S. KAJIGAESHI, S. KAJIGAESHI Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. KAKINAMI, T. KAKINAMI Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorH. TOKIYAMA, H. TOKIYAMA Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. HIRAKAWA, T. HIRAKAWA Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. OKAMOTO, T. OKAMOTO Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this author S. KAJIGAESHI, S. KAJIGAESHI Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. KAKINAMI, T. KAKINAMI Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorH. TOKIYAMA, H. TOKIYAMA Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. HIRAKAWA, T. HIRAKAWA Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this authorT. OKAMOTO, T. OKAMOTO Dep. Ind. Chem., Fac. Eng., Yamaguchi Univ., Tokiwadai, Ube, Yamaguchi 755, JapanSearch for more papers by this author First published: November 24, 1987 https://doi.org/10.1002/chin.198747124Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume18, Issue47November 24, 1987 RelatedInformation