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Environment - friendly bromination of aromatic heterocycles using a bromide – bromate couple in an aqueous medium / Girdhar Joshi in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12271-12275 Titre : Environment - friendly bromination of aromatic heterocycles using a bromide – bromate couple in an aqueous medium Type de document : texte imprimé Auteurs : Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur Année de publication : 2011 Article en page(s) : pp. 12271-12275 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous  medium  Bromination Résumé : Selective monobromination of aromatic heterocyclic compounds through in-situ acid activation of 2:1 bromide/ bromate couple as a benign brominating reagent is described. The in-situ acid activation of a bromide-bromate couple generates the reactive species BrOH, and it is proved to be an efficient for the bromination of various heterocycles under mild aqueous conditions without the use of any catalyst. Heterocycles that had electron-rich substituents provided good yields. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697546 [article] Environment - friendly bromination of aromatic heterocycles using a bromide – bromate couple in an aqueous medium [texte imprimé] / Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur . - 2011 . - pp. 12271-12275. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12271-12275 Mots-clés : Aqueous  medium  Bromination Résumé : Selective monobromination of aromatic heterocyclic compounds through in-situ acid activation of 2:1 bromide/ bromate couple as a benign brominating reagent is described. The in-situ acid activation of a bromide-bromate couple generates the reactive species BrOH, and it is proved to be an efficient for the bromination of various heterocycles under mild aqueous conditions without the use of any catalyst. Heterocycles that had electron-rich substituents provided good yields. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697546

HBr−H2O2: a facile protocol for regioselective synthesis of bromohydrins and α-bromoketones and oxidation of benzylic/secondary alcohols to carbonyl compounds under mild aqueous conditions / Rajendra D. Patil in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8100–8105 Titre : HBr−H2O2: a facile protocol for regioselective synthesis of bromohydrins and α-bromoketones and oxidation of benzylic/secondary alcohols to carbonyl compounds under mild aqueous conditions Type de document : texte imprimé Auteurs : Rajendra D. Patil, Auteur ; Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur Année de publication : 2010 Article en page(s) : pp 8100–8105 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bromohydrins  Oxidation  benzylic  Mild  aqueous. Résumé : HBr−H2O2 is efficiently activated in water under mild conditions, allowing the bromohydroxylation of various styrenes. HBr−H2O2 is more economic and easy to handle and offers sufficiently high regioselectivity (100%) for bromohydrin synthesis. Further activation of bromohydrin with a catalytic amount of HBr (50 mol %) and H2O2 in water affords α-bromoketones in moderate to good yields in a single step. Oxidation of benzylic/secondary alcohols to the corresponding carbonyl compounds has been achieved with the HBr (10 mol %) and H2O2 efficiently in aqueous dioxane under ambient conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100492r [article] HBr−H2O2: a facile protocol for regioselective synthesis of bromohydrins and α-bromoketones and oxidation of benzylic/secondary alcohols to carbonyl compounds under mild aqueous conditions [texte imprimé] / Rajendra D. Patil, Auteur ; Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur . - 2010 . - pp 8100–8105. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8100–8105 Mots-clés : Bromohydrins  Oxidation  benzylic  Mild  aqueous. Résumé : HBr−H2O2 is efficiently activated in water under mild conditions, allowing the bromohydroxylation of various styrenes. HBr−H2O2 is more economic and easy to handle and offers sufficiently high regioselectivity (100%) for bromohydrin synthesis. Further activation of bromohydrin with a catalytic amount of HBr (50 mol %) and H2O2 in water affords α-bromoketones in moderate to good yields in a single step. Oxidation of benzylic/secondary alcohols to the corresponding carbonyl compounds has been achieved with the HBr (10 mol %) and H2O2 efficiently in aqueous dioxane under ambient conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100492r

Making full use of the oxidizing equivalents in bromate in the selective oxidation of thiols, sulfides, and benzylic/secondary alcohols into disulfides, sulfoxides, and aldehydes/Kketones / Girdhar Joshi in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1236–1241 Titre : Making full use of the oxidizing equivalents in bromate in the selective oxidation of thiols, sulfides, and benzylic/secondary alcohols into disulfides, sulfoxides, and aldehydes/Kketones Type de document : texte imprimé Auteurs : Girdhar Joshi, Auteur ; Sukalyan Bhadra, Auteur ; Sudip Ghosh, Auteur ; Manoj K. Agrawal, Auteur Année de publication : 2010 Article en page(s) : pp. 1236–1241 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Making  Full--Oxidizing--Equivalents--Bromate--Selective--Oxidation  --Sulfides--Benzylic--Secondary--Alcohols--Disulfides--Sulfoxides,  --Aldehydes--Ketones Résumé : The oxidation of thiols to disulfides was achieved in high yields with 6:1 mol ratio of thiol to NaBrO3, while the oxidation of sulfides and benzylic/secondary alcohols to the corresponding sulfoxides and aldehydes/ketones was successfully undertaken with 3:1 mol ratio of substrate to NaBrO3. These ratios correspond to the minimum theoretical requirement of NaBrO3. The reactions were conducted at 0−30 °C, depending upon substrate, and were initiated with catalytic amounts of H+ and Br− (initial Br−/BrO3− = 1:3.5 for thiol oxidation and 1:8 for sulfide and alcohol oxidation). Further, regeneration and reuse of the spent reagent in the aqueous effluent was demonstrated. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901426t [article] Making full use of the oxidizing equivalents in bromate in the selective oxidation of thiols, sulfides, and benzylic/secondary alcohols into disulfides, sulfoxides, and aldehydes/Kketones [texte imprimé] / Girdhar Joshi, Auteur ; Sukalyan Bhadra, Auteur ; Sudip Ghosh, Auteur ; Manoj K. Agrawal, Auteur . - 2010 . - pp. 1236–1241. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1236–1241 Mots-clés : Making  Full--Oxidizing--Equivalents--Bromate--Selective--Oxidation  --Sulfides--Benzylic--Secondary--Alcohols--Disulfides--Sulfoxides,  --Aldehydes--Ketones Résumé : The oxidation of thiols to disulfides was achieved in high yields with 6:1 mol ratio of thiol to NaBrO3, while the oxidation of sulfides and benzylic/secondary alcohols to the corresponding sulfoxides and aldehydes/ketones was successfully undertaken with 3:1 mol ratio of substrate to NaBrO3. These ratios correspond to the minimum theoretical requirement of NaBrO3. The reactions were conducted at 0−30 °C, depending upon substrate, and were initiated with catalytic amounts of H+ and Br− (initial Br−/BrO3− = 1:3.5 for thiol oxidation and 1:8 for sulfide and alcohol oxidation). Further, regeneration and reuse of the spent reagent in the aqueous effluent was demonstrated. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901426t