- A useful propionate cofactor enhancing activity for organic solvent-tolerant recombinant metal-free bromoperoxidase (perhydrolase) from Streptomyces aureofaciens
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The oxidative brominating activity of an organic solvent-tolerant recombinant metal-free bromoperoxidase BPO-A1 with C-terminal His-tag (rBPO-A1), from Streptomyces aureofaciens found to depend on various additives. These included carboxylic acids, used as cofactors and alcohols, used as water-miscible organic solvents. Enzyme activity was significantly enhanced by using propanoic acid (PA) as a cofactor, which had a high Log D at pH 5.0 and ethylene glycol with a low Log P. The positional specificity of oxidative hydroxybromination for olefins, using rBPO-A1 and PA in the presence of methanol, was higher compared to a non-enzymatic reaction using peracetic acid. The oxidative bromination step, occurring after enzymatic peroxidation step, is suggested to be pseudoenzymatic.
- China, Hideyasu,Ogino, Hiroyasu
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p. 327 - 332
(2019/07/12)
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- On the bromination of aromatics, alkenes and alkynes using alkylammonium bromide: Towards the mimic of bromoperoxidases reactivity
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This article describes an efficient method of bromination of organic substrates including aromatics, alkenes and alkynes with NH4VO3as a catalyst and H2O2as an oxidant agent using a non-toxic and easy-to-handle source of bromine, tetrabutylammonium bromide. The process was developed under mild reaction conditions and is an innovation from reported methods in aspects such as: i) short reaction times, ii) the ability to work at room temperature, iii) regioselectivity and good yields.
- Mendoza, Fabian,Ruíz-Guerrero, Rosario,Hernández-Fuentes, Carlos,Molina, Paulina,Norzagaray-Campos, Mariano,Reguera, Edilso
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supporting information
p. 5644 - 5648
(2016/11/28)
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- Facile one-pot synthesis of α-bromoketones from olefins using bromide/bromate couple as a nonhazardous brominating agent
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A new method for the preparation of α-bromoketones from olefins using bromide/bromate couple as a nonhazardous brominating agent has been developed. Several α-bromoketones were successfully prepared from a variety of olefins by this method. This procedure is an alternative to conventional molecular bromine.
- Patil, Rajendra D.,Joshi, Girdhar,Adimurthy, Subbarayappa,Ranu, Brindaban C.
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experimental part
p. 2529 - 2532
(2009/09/06)
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- Process for producing Trans-2 bromoindan-1-ol
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A cheap industrial method for making trans-2-bromoindan-1-ol. Trans-2-bromoindan-1-ol represented by Formula (II) is made by hydrolysing 1,2-dibromoindane represented by General Formula (I) (where the configuration of the bromine atoms on position 1 and position 2 can be trans or cis, or it can be a mixture of trans and cis isomers). Trans-2-bromoindan-1-ol represented by Formula (II) can also be made by brominating indene to synthesize 1,2-dibromoindane, and then continuously hydrolysing this 1,2-dibromoindane without isolating it. 1,2-Dibromoindane can also be made by reacting indene with hydrogen bromide in the presence of hydrogen peroxide.
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- Synthesis of brominated compounds. A convenient molybdenum-catalyzed procedure inspired by the mode of action of haloperoxidases
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A two-phase (CHCl3/H2O) procedure for the synthesis of halogenated compounds has recently been developed. Such procedure mimics the mode of action of the enzymes haloperoxidases which contain vanadium in their active center. We have investigated the possibility to substitute vanadium with molybdenum. The molybdenum-based reactions show some advantages over the vanadium-based ones. In fact reaction times are shorter and overall yields are larger, under similar experimental conditions, both in the reaction with double bonds as well as with aromatic rings. Moreover, with double bonds, the molybdenum catalyzed process preferentially yields bromohydrins which are valuable synthetic intermediates. On the other hand, the molybdenum-catalyzed reactions show peculiar mechanistic features which deserve further investigation.
- Conte, Valeria,Di Furia, Fulvio,Moro, Stefano
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p. 8609 - 8612
(2007/10/03)
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- POTASSIUM BROMIDE / m-CHLOROPERBENZOIC ACID / 18-CROWN-6. A CONVENIENT REAGENT FOR THE PREPARATION OF trans 1,2-BROMOCARBOXYLATES
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In the presence of 18-crown-6 (10 mmolpercent), potassium bromide reacts with m-CIPBA to form m-chlorobenzoylhypobromite.The latter readily adds across carbon-carbon double bonds to furnish 1,2-bromocarboxylates in a highly regio- and stereospecific manne
- Srebnik, Morris
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p. 197 - 206
(2007/10/02)
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