7429-37-0Relevant academic research and scientific papers
Linear Paired Electrolysis—Realising 200 % Current Efficiency for Stoichiometric Transformations—The Electrochemical Bromination of Alkenes
Strehl, Julia,Abraham, Marvin L.,Hilt, Gerhard
supporting information, p. 9996 - 10000 (2021/03/31)
The generation of bromine by oxidation of bromide anions at the anode and reduction of molecular oxygen at the cathode to hydrogen peroxide resulted in the overall formation of two molecules of Br2 (=four electron oxidation) by passing just two electrons through the solution. The bromine was used for the bromination of alkenes and thereby a linear paired electrolysis was attained which resulted in current efficencies of up to 200 %. Also, the diiodination of cyclohexene as well as the electrophilic aromatic bromination of an electron-rich arene were realised both in 168 % current efficiencies.
Dibrominated addition and substitution of alkenes catalyzed by Mn2(CO)10
Chan, Albert S. C.,Jiang, Yi,Meng, Shanshui,Song, Xianheng,Zhang, Hong,Zou, Yong
supporting information, p. 13385 - 13388 (2021/12/17)
A practical method for the dibromination of alkenes without using molecular bromine is consistently appealing in organic synthesis. Herein, we report Mn-catalyzed dibrominated addition and substitution of alkenes only with N-bromosuccinimide, producing a variety of synthetically valuable dibrominated compounds in moderate to high yields. This journal is
Green bromination method
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Paragraph 0068-0070, (2021/06/13)
The invention discloses a green bromination method, and belongs to the field of green organic chemistry. Under the conditions of room temperature, opening and neutrality, reaction raw materials are aromatic hydrocarbon, olefin, alkyne, tryptamine, tryptophane and derivatives thereof with different functional groups, a bromine source is MBrx (M is Fe , Fe , Ce and the like, and x is 2-3), and the unique oxidant is H2O2. Brominated alkanes, alkenes, aromatic hydrocarbons, pyrrolo-indolines and furo-indolines and derivatives thereof can be produced. The bromination reaction is carried out by using easily available and cheap reagents (such as FeBr2, CeB3 and H2O2) in the market and the solvent, and the method has the characteristics of mild reaction conditions, wide substrate application range, simple steps, easiness in operation and no need of separation, is a green, environment-friendly and safe bromination reaction method, and has a good application prospect.
Tandem Deoxygenation/Halogenation of N-Oxides Under Acylation Conditions: Scope and In Situ IR Spectroscopic Study
Malykhin, Roman S.,Golovanov, Ivan S.,Ioffe, Sema L.,Sukhorukov, Alexey Yu.
, p. 4139 - 4148 (2019/04/03)
Acylation of cyclic nitronates with acyl bromides produces 3-bromomethyl-substituted 5,6-dihydro-2H-1,2-oxazines via an unusual multi-stage process involving deoxygenation of N-oxide and the formation of Br2. Low-temperature in situ ATR FT-IR monitoring and DFT calculations revealed α-halo-substituted N,N-bis(oxy)amines as key intermediates of the process. The developed method was successfully exploited in the stereoselective synthesis of pharmaceutically relevant molecules.
A bromo-capped diruthenium(i,i) N-heterocyclic carbene compound for in situ bromine generation with NBS: Catalytic olefin aziridination reactions
Sengupta, Gargi,Pandey, Pragati,De, Subhabrata,Ramapanicker, Ramesh,Bera, Jitendra K.
, p. 11917 - 11924 (2018/09/10)
A bromo-capped metal-metal bonded diruthenium(i,i) complex Ru2(CO)4(PIN)2Br2 (1) (PIN = 1-isopropyl-3-(5,7-dimethyl-1,8-naphthyrid-2-yl)imidazol-2-ylidene) generates bromine with N-bromosuccinimide (NBS) at room temperature. Cycloalkene and stilbene are readily brominated by stoichiometric reactions with 1 and NBS. An analysis of the dibrominated products suggests the formation of cyclic bromonium intermediates indicating in situ Br2 generation. Complex 2, an iodide analogue of 1, is also synthesized. The reaction of 2 with N-iodosuccinimide releases I2, which is confirmed by the starch-iodine test. The catalytic utility of 1 is examined for the bromination of phenol. Catalyst 1, in combination with NBS and base, exhibits regioselectivity towards monobrominated products. Furthermore, efficient olefin aziridination is demonstrated utilizing catalyst 1 in the presence of NBS, K2CO3 and TsNH2.
A Highly Efficient Method for the Bromination of Alkenes, Alkynes and Ketones Using Dimethyl Sulfoxide and Oxalyl Bromide
Ding, Rui,Li, Jiaqi,Jiao, Wenyi,Han, Mengru,Liu, Yongguo,Tian, Hongyu,Sun, Baoguo
, p. 4325 - 4335 (2018/11/21)
The pairing of DMSO and oxalyl bromide is reported as a highly efficient brominating reagent for various alkenes, alkynes and ketones. This bromination approach demonstrates remarkable advantages, such as mild conditions, low cost, short reaction times, provides excellent yields in most cases and represents a very attractive alternative for the preparation of dibromides and α-bromoketones.
Dibromination of alkenes with LiBr and H2O2 under mild conditions
Martins, Nayara Silva,Alberto, Eduardo E.
supporting information, p. 161 - 167 (2017/12/28)
Electron-rich and electron-poor alkenes, and alkenes bearing protecting groups can be efficiently and stereoselectively converted to trans-dibromides using LiBr/H2O2 and AcOH as a proton source in 1,4-dioxane. For most substrates addition of 0.1 mol% of PhTeTePh enhances the reaction rate and the yield of the products. Experimental data suggest that the brominating agent prepared in situ is molecular bromine and that LiBr assists the activation of H2O2 allowing bromination to occur using AcOH as a mild proton source in uncatalyzed experiments. Scale-up is feasible: 10.0 mmol of 1-octene was quantitatively converted to 1,2-dibromooctene in one hour of reaction at room temperature.
Mild and Efficient Vicinal Dibromination of Olefins Mediated by Aqueous Ammonium Fluoride
Ng, Wing Hin,Shing, Tony K. M.,Yeung, Ying-Yeung
supporting information, p. 419 - 424 (2018/02/23)
A mild and efficient vicinal dibromination of olefins has been developed by using saturated aqueous ammonium fluoride solution as the promoter. Inexpensive and commercially available N -bromosuccinimide (NBS) was used as the brominating reagent. The corresponding vicinal dibromoalkanes could be obtained in good to excellent yields.
Intermolecular Halogenation/Esterification of Alkenes with N-Halosuccinimide and Acetic Acid Catalyzed by 1,4-Diazabicyclo[2.2.2]octane
Pimenta, Laura S.,Gusevskaya, Elena V.,Alberto, Eduardo E.
supporting information, p. 2297 - 2303 (2017/07/07)
1,4-Diazabicyclo[2.2.2]octane (DABCO) is a suitable Lewis base that acts as an organocatalyst in the activation of N-chlorosuccinimide (NCS) towards the chlorination of alkenes. The chloriranium ion formed from NCS and the alkene, can be intermolecularly opened by a nucleophile, such as acetic acid, to produce highly functionalized trans-chloro esters in high yields. The protocol is also applied to the synthesis of chlorohydrins and chloro ethers using water or methanol as nucleophiles instead of acetic acid. Brominated analogs can also be synthesized from alkenes and N-bromosuccinimide (NBS) in the presence of various basic catalysts. However, the reaction patterns seem to be remarkably different. The catalytic performance of bases in the bromoesterification of alkenes was found to be strongly affected by their Br?nsted basicity, suggesting that acetyl hypobromite, formed in situ from NBS and acetic acid, acts as a real brominating agent in these systems. (Figure presented.).
Preparation of manganese/Graphite oxide composite using permanganate and graphite: Application as catalyst in bromination of hydrocarbons
Suzuki, Hideyuki,Nishina, Yuta
supporting information, p. 74 - 78 (2017/08/14)
A highly efficient one-pot preparation of manganese/graphite oxide (MnOX/GO) composite from graphite and KMnO4 is described. Hummers preparation method of GO requires a stoichiometric amount of KMnO4, as a result, the method produces a large amount of reduced Mn species. The Mn residue generally is a waste, therefore, we envisioned converting it to value-Added materials. A MnOX/GO composite was prepared in one-pot by treating the unpurified GO with aqueous KOH. The composite was characterized by XRD, XAFS, SEM and TEM. Among various applications of the MnOX/GO composite, we applied it as a recyclable catalyst for bromination of saturated hydrocarbons, one of the most basic but important chemical transformations. The MnOX/GO composite is expected to be an efficient catalyst because of the high surface area and high accessibility of substrates derived from the 2- dimensional sheet structure. When the reaction of a saturated hydrocarbon and Br2 in the presence of catalytic MnOX/GO was performed under fluorescent light irradiation, a brominated product was formed in high yield in a short reaction time. GO could strongly bind with Mn to prevent elution to the liquid phase, enabling the high recyclability.
