557-35-7Relevant academic research and scientific papers
Kinetics of 'initial burst' in the solid-liquid phase-transfer catalysis. Nucleophilic substitution of 2-octyl mesylate with potassium bromide
Yufit,Zinovyev
, p. 343 - 348 (2001)
The SN2 substitution of 2-octyl mesylate with solid KBr under the conditions of phase-transfer catalysis was studied kinetically using the model approach of 'initial burst.' It is suggested that such kinetics reflect the contribution of mass transfer and surface poisoning. The proposed model is used to explain the influences of catalyst, solvent, stirring speed, activation and agitation effects. The mechanistic scheme suggests that the reaction is described by two separate kinetic stages, one of which reflects the intrinsic rate-limited step and the other the mass transfer-controlled step. Copyright
An Unusually Mild and Selective Bromination of Some n-Alkanes with Barium Tetrafluorobromate
Sobolev,Ostvald,Zherin,Shushpanova,Filimonov
, p. 297 - 299 (2021/03/26)
Abstract: Barium tetrafluorobromate Ba(BrF4)2 is a brominating agent for hexane, octane, and decane. The reaction occurs under very mild conditions at –25 to –20°C and results in preferential formation of 2-bromoalkanes.
Construction of chiral liquid crystal phosphorescent material based on cyclometalated platinum complex and application of chiral liquid crystal phosphorescent material in circular polarizer
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Paragraph 0021, (2020/06/09)
The invention discloses a chiral liquid crystal luminescent material based on a cyclometalated platinum complex and application of the chiral liquid crystal luminescent material. According to the invention, the cyclometalated platinum complex is used as a light-emitting core, and chiral alkyl chains and liquid crystal elements are respectively introduced to the peripheries of a main ligand and anauxiliary ligand to construct the chiral liquid crystal phosphorescent material. The material shows effective circular polarization luminescence performance in a solid film. The cyclometalated platinum complex is used as a doping agent of a light-emitting layer; a circular polarization organic light-emitting device is prepared through a solution method, the maximum external quantum efficiency is 11.3%, and the maximum electrogenerated circular polarization light-emitting asymmetry factor (glum) is 0.06; and the annealing temperature of the light-emitting layer has great influence on the circular polarization light-emitting performance of the device. The invention provides a research thought for constructing the efficient chiral liquid crystal phosphorescent material.
Sodium diisopropylamide-mediated dehydrohalogenations: Influence of primary- A nd secondary-shell solvation
Ma, Yun,Algera, Russell F.,Woltornist, Ryan A.,Collum, David B.
supporting information, p. 10860 - 10869 (2019/09/30)
Eliminations of alkyl halides by sodium diisopropylamide (NaDA) in tetrahydrofuran (THF)/hexane or THF/N,N-dimethylethylamine (DMEA) solutions are facile and complementary to analogous reactions of lithium diisopropylamide in THF. Rate studies show a dominance of monomer-based metalations and prevalent secondary-shell solvation effects overlaid on primary-shell effects. 1-Halooctanes exclusively undergo elimination rather than substitution. Rate and isotopic labeling studies on 1-bromooctane reveal an E2-like elimination pathway via trisolvated NaDA monomer. By contrast, 1-chlorooctane is eliminated via disolvated monomer through a carbenoid mechanism. exo-2-Norbornyl chloride and bromide are also eliminated via disolvated monomer; a syn E2 mechanism is inferred for these substrates. The cis- A nd trans-4-tert-butylcyclohexyl bromides show a preference for the elimination of the cis isomer (kcis/ax/ktrans/eq = 10). Rate and isotopic labeling studies are consistent with a trans-diaxial E2 elimination via trisolvated monomer for the cis isomer and a carbenoid mechanism via disolvated monomer for the trans isomer. Vicinal haloethers show substrate-dependent reactivities, affording alkynes and enol ethers. trans-1-Bromo-2-methoxycyclohexane provides enol ether 1-methoxycyclohexene, while trans-1-bromo-2-methoxycyclooctane provides dimeric products consistent with fleeting cycloocta-1,2-diene (cyclic allene), which was fully characterized as two conformers.
Palladium-Catalyzed Alkoxycarbonylation of Unactivated Secondary Alkyl Bromides at Low Pressure
Sargent, Brendon T.,Alexanian, Erik J.
supporting information, p. 7520 - 7523 (2016/07/06)
Catalytic carbonylations of organohalides are important C-C bond formations in chemical synthesis. Carbonylations of unactivated alkyl halides remain a challenge and currently require the use of alkyl iodides under harsh conditions and high pressures of CO. Herein we report a palladium-catalyzed alkoxycarbonylation of secondary alkyl bromides that proceeds at low pressure (2 atm CO) under mild conditions. Preliminary mechanistic studies are consistent with a hybrid organometallic-radical process. These reactions efficiently deliver esters from unactivated alkyl bromides across a diverse range of substrates and represent the first catalytic carbonylations of alkyl bromides with carbon monoxide.
A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity
Munyemana, Fran?ois,George, Isabelle,Devos, Alain,Colens, Alain,Badarau, Eduard,Frisque-Hesbain, Anne-Marie,Loudet, Aurore,Differding, Edmond,Damien, Jean-Marie,Rémion, Jeanine,Van Uytbergen, Jacqueline,Ghosez, Léon
, p. 420 - 430 (2015/12/31)
α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.
An efficient and selective method for the iodination and bromination of alcohols under mild conditions
Khazdooz, Leila,Zarei, Amin,Aghaei, Hamidreza,Azizi, Ghobad,Gheisari, Mohammad Mehdi
, p. 168 - 171 (2015/12/30)
A straightforward and effective procedure for the conversion of a variety of alcohols into the corresponding alkyl iodides and bromides is described using KX/P2O5 (X = I, Br). The reactions were easily carried out in acetonitrile under mild conditions. Using this method, the selective conversion of benzylic alcohols in the presence of aliphatic alcohols was achieved.
Tribromoisocyanuric acid/triphenylphosphine: A new system for conversion of alcohols into alkyl bromides
De Andrade, Vitor S.C.,De Mattos, Marcio C.S.
, p. 975 - 979 (2014/06/24)
An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/ tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzylic and allylic alcohols, and their corresponding bromides are obtained in 67-82 percent yield. Tertiary alcohols do not react under these conditions.
Copper-catalyzed alkyl-alkyl cross-coupling reactions using hydrocarbon additives: Efficiency of catalyst and roles of additives
Iwasaki, Takanori,Imanishi, Reiko,Shimizu, Ryohei,Kuniyasu, Hitoshi,Terao, Jun,Kambe, Nobuaki
, p. 8522 - 8532 (2015/01/08)
Cross-coupling of alkyl halides with alkyl Grignard reagents proceeds with extremely high TONs of up to 1230000 using a Cu/unsaturated hydrocarbon catalytic system. Alkyl fluorides, chlorides, bromides, and tosylates are all suitable electrophiles, and a TOF as high as 31200 h-1 was attained using an alkyl iodide. Side reactions of this catalytic system, i.e., reduction, dehydrohalogenation (elimination), and the homocoupling of alkyl halides, occur in the absence of additives. It appears that the reaction involves the β-hydrogen elimination of alkylcopper intermediates, giving rise to olefins and Cu-H species, and that this process triggers both side reactions and the degradation of the Cu catalyst. The formed Cu-H promotes the reduction of alkyl halides to give alkanes and Cu-X or the generation of Cu(0), probably by disproportionation, which can oxidatively add to alkyl halides to yield olefins and, in some cases, homocoupling products. Unsaturated hydrocarbon additives such as 1,3-butadiene and phenylpropyne play important roles in achieving highly efficient cross-coupling by suppressing β-hydrogen elimination, which inhibits both the degradation of the Cu catalyst and undesirable side reactions.
In situ generated Ph3P(OAc)2as a novel reagent for the efficient acetylation of alcohols and thiols at room temperature
Iranpoor, Nasser,Firouzabadi, Habib,Elham, Etemadi Davan
, p. 1813 - 1816 (2013/04/24)
Ph3P, Br2, and ammonium acetate are used for the in situ generation of Ph3P(OAc)2, which was characterized by different NMR techniques. The Ph3P(OAc)2generated was used as a novel and efficient reagent for the acetylation of alcohols and thiols in acetonitrile at room temperature under homogeneous conditions. This reaction was also performed under heterogeneous conditions using 1,3,2,4- diazadiphosphetidine as an easily prepared, stable, and heterogeneous P(III) compound.
