100227-07-4Relevant articles and documents
79Br NMR spectroscopy as a practical tool for kinetic analysis
Chan, Si Jia,Howe, Andrew G.,Hook, James M.,Harper, Jason B.
, p. 342 - 347 (2009)
79Br NMR spectroscopy has been used to monitor a series of reactions in which the bromide ion is produced, including the Menschutkin reaction of pyridine with a range of substituted benzyl bromides and a Heck coupling process. In cases where the process could also be monitored using 1H NMR spectroscopy, the kinetic analyses using heteronuclear magnetic resonance spectroscopy were shown to be completely consistent. Both the utility of the process in following reactions which may be difficult to analyse using other techniques and the practical limitations associated with solvent choice are discussed. Copyright
Direct sustainable bromination of alkenes in aqueous media and basic ionic liquids
Primerano, Patrizia,Cordaro, Massimiliano,Scala, Angela
, p. 4061 - 4063 (2013)
Electron-rich and electron-poor alkenes have been dibrominated using a rapid and sustainable procedure. The reactions were conducted in aqueous medium and basic ionic liquids which catalyzed the direct addition of bromine. The protocol leads to remarkable results, high yields under mild conditions, complete chemo- and stereo-selectivity and allows the recycling of ionic liquids, reducing costs, and environmental impact.
Quantitative structure-activity relationships of pine weevil antifeedants, a multivariate approach
Sunnerheim, Kerstin,Nordqvist, Anneli,Nordlander, Goeran,Borg-Karlson, Anna-Karin,Unelius, C. Rickard,Bohman, Bjoern,Nordenhem, Henrik,Hellqvist, Claes,Karlen, Anders
, p. 9365 - 9372 (2007)
Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abietis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active antifeedants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeedant activity.
A General Method for the Dibromination of Vicinal sp3C-H Bonds Exploiting Weak Solvent-Substrate Noncovalent Interactions
Qi, Zaojuan,Li, Weihe,Niu, Yanning,Benassi, Enrico,Qian, Bo
supporting information, p. 2399 - 2404 (2021/03/03)
A general procedure of 1,2-dibromination of vicinal sp3 C-H bonds of arylethanes using N-bromosuccinimide as the bromide reagent without an external initiator has been established. The modulation of the strength of the intermolecular noncovalent interactions between the solvent and arylethane ethanes, quantitatively evaluated via quantum chemical calculations, allows us to circumvent the fact that arylethane ethane cannot be dibrominated through traditional methods. The mechanism was explored by both experiments and quantum chemical calculations, revealing a radical chain with HAA process.
Preparation method of 1-aryl-1,2-dibromoethane
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Paragraph 0023-0024, (2020/03/16)
The invention relates to a preparation method of 1-aryl-1,2-dibromoethane. The preparation method of 1-aryl-1,2-dibromoethane includes the steps: under a nitrogen atmosphere, a solvent, an aryl alkaneand N-bromosuccinimide are added in to a reaction tube in sequence, a dibromination reaction is conducted at 80-120 DEG C for 12-48 hours, then, the dibromination reaction is finished, the solvent isremoved through evaporation, and through column chromatography separation, 1-aryl-1,2-dibromoethane compounds are obtained. According to the preparation method of 1-aryl-1,2-dibromoethane, a synthesis technology is simple, reaction conditions are mild, the yield of 1-aryl-1,2-dibromoethane is high, and thus the preparation method of 1-aryl-1,2-dibromoethane is easy to industrialize.
PPh3O as an Activating Reagent for One-Pot Stereoselective Syntheses of Di- and Polybrominated Esters from Simple Aldehydes
Yu, Tian-Yang,Wei, Hao,Luo, Yong-Chun,Wang, Yao,Wang, Zhu-Yin,Xu, Peng-Fei
, p. 2730 - 2736 (2016/04/26)
(Chemical Equation Presented) An efficient one-pot method for the syntheses of di- and polybrominated esters from readily available aldehydes is reported. The direct use of the in situ generated byproduct PPh3O in the following reactions greatly improves the efficiency of the cascade. Also, the substrate scope of the reaction is proved to be broad.
Triphenylphosphine oxide-catalyzed stereoselective poly- and dibromination of unsaturated compounds
Yu, Tian-Yang,Wang, Yao,Hu, Xiu-Qin,Xu, Peng-Fei
supporting information, p. 7817 - 7820 (2014/07/08)
A novel PPh3O catalyzed bromophosphonium salt-mediated dibromination of α,β-unsaturated esters and β,γ- unsaturated α-ketoesters has been developed. The products were obtained with good to excellent yields and excellent diastereoselectivities.
Halocarbocyclization versus dihalogenation: Substituent directed iodine(iii) catalyzed halogenations
Stodulski, Maciej,Goetzinger, Alissa,Kohlhepp, Stefanie V.,Gulder, Tanja
supporting information, p. 3435 - 3438 (2014/03/21)
The nucleophilicity of the substituents in iodobenzene pre-catalysts have a huge impact on product selectivity in iodine(iii) triggered halogenations, steering the reactivity from solely carbocyclizations towards dihalogenations. Utilizing this catalyst-dependent reactivity a diastereo- and chemoselective dihalogenation method was established allowing the conversion of structurally and electronically diverse unsaturated compounds in excellent yields.
Aqueous Et4NBrO3/KBr as a versatile and environmentally benign source of bromine for the selective trans-bromination of alkenes
Das, Pranab Jyoti,Sarkar, Sudeshna
, p. 802 - 806 (2013/07/26)
An aqueous solution of tetraethyl ammonium bromate and potassium bromide is found to be an environmentally benign source of bromine at ambient temperature. This reagent is used for selective trans-dibromination of several substituted alkenes. The reaction conditions are mild and the yield of the products are high and other possible by-products such as bromohydrin formation and aromatic substitution have not been observed.
Magnetic-nanoparticle-supported 2,2′-bis[3-(triethoxysilyl)propyl] imidazolium-substituted diethyl ether bis(tribromide): A convenient recyclable reagent for bromination
Wu, Liqiang,Yin, Zhikui
, p. 6156 - 6163 (2014/01/06)
A new magnetic-nanoparticle-supported bromination reagent was synthesized by anchoring a 2,2′-bis[3-(triethoxysilyl)propyl]imidazolium-substituted diethyl ether bis(tribromide) onto the surface of γ-Fe2O 3 nanoparticles and subsequently treating this new ionic liquid with bromine. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. More importantly, the reagent could be easily recovered by an external magnet and reused six times without significant loss of activity. A new maghemite nanoparticle bromination reagent has been prepared. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. Copyright
