13651-05-3Relevant academic research and scientific papers
Chemoselective bromination in a two-step substitution under the influence of tetrachlorosilane and N-bromosuccinimide
Elmorsy, Saad,Badawy, Doria,Khatab, Tamer
, p. 2005 - 2012 (2006)
The synthesis of gem dibromide carbonyl compounds via a cheep and readily available combined reagent from tetrachlorosilane and N-bromosuccinimide (TCS-NBS). Copyright Taylor & Francis Group, LLC.
Access to α,α-dihaloacetophenones through anodic C[dbnd]C bond cleavage in enaminones
Zhang, Zhenlei,Yang, Jiusi,Wu, Kairui,Yu, Renjie,Bu, Jiping,Huang, Zijun,Li, Shaoke,Ma, Xiantao
supporting information, (2021/12/20)
We have developed a method to synthesize α,α-dihaloketones under electrochemical conditions. In this reaction, the Cl- or Br- is oxidized to Cl2 or Br2 at the anode, which undergoes two-step addition reactions with the N,N-dimethyl enaminone, and finally breaks C[dbnd]C of the N,N-dimethyl enaminone to generate α,α-dihaloketones. The electrosynthesis reaction can be conveniently carried out in an undivided electrolytic cell at room temperature. In addition, various functional groups are compatible with this green protocol which can be applied simultaneously to the gram scale without significantly lower yield.
Electrochemical Oxidative Functionalization of Arylalkynes: Access to α,α-Dibromo Aryl Ketones
Wang, Dan,Wan, Zhaohua,Zhang, Heng,Lei, Aiwen
supporting information, p. 1022 - 1027 (2020/12/31)
A general and effective protocol to synthesize α,α-dibromo aryl ketones has been developed via an electrochemical oxidative method. The reaction proceeds smoothly at room temperature in an undivided cell without the addition of external oxidants. In the reaction process, LiBr acts as both bromine source and supporting electrolyte. This electrooxidation strategy has good substrate applicability and functional group compatibility. Moreover, the reaction could be scaled up efficiently in a continuous flow cell. The target product could undergo further functionalization for the synthesis of some useful heterocyclic compounds. (Figure presented.).
Selective Debromination of α,α,α-Tribromomethylketones with HBr–H2O Reductive Catalytic System
Cheng, Zhao,Guo, Hongmei,Huang, Guozheng,Rexit, Abulikemu Abudu,Wang, Hui,Zheng, Meng-Xia
, p. 6455 - 6458 (2020/10/21)
A debromination of α,α,α-tribromomethylketones is developed for chemoselective synthesis of α-mono- and α,α-dibromomethylketones with high selectivity under H2O–HBr reductive conditions. This method offers an efficient and direct way to synthesize α-mono or α,α-dibromomethylketone compounds in high to excellent yields through the process of HBr self-circulation in water.
Switchable Synthesis of α,α-Dihalomethyl and α,α,α-Trihalomethyl Ketones by Metal-Free Decomposition of Enaminone C=C Double Bond
Liu, Yunyun,Xiong, Jin,Wei, Li,Wan, Jie-Ping
supporting information, p. 877 - 883 (2020/01/24)
The novel free radical-based cleavage of the enaminone C=C double bond is realized by using N-halosuccinimides (NXS) in the presence of benzoyl peroxide (BPO) with mild heating, enabling the tunable synthesis of α,α-dihalomethyl ketones and α,α,α-trihalomethyl ketones under different reaction conditions. The formation of these divergent products involving featured C=C double bond cleavage requires no any metal reagent, and represents one more practical example on the synthesis of poly halogenated methyl ketones via the functionalization of carbon?carbon bond. (Figure presented.).
Water-controlled selective preparation of α-mono or α,α′-dihalo ketones: Via catalytic cascade reaction of unactivated alkynes with 1,3-dihalo-5,5-dimethylhydantoin
Wu, Chao,Xin, Xiu,Fu, Zhi-Min,Xie, Long-Yong,Liu, Kai-Jian,Wang, Zheng,Li, Wenyi,Yuan, Zhi-Hui,He, Wei-Min
, p. 1983 - 1989 (2017/06/09)
The control of a reaction that can produce multiple products from the same starting material is a highly attractive and challenging concept in organic synthesis. An efficient protocol for the selective synthesis of α-mono or α,α′-dihalo ketones via a water-controlled three-component thiourea-catalyzed cascade reaction of unactivated alkynes, 1,3-dihalo-5,5-dimethylhydantoin and water has been developed. α-Monohaloketones were obtained in aqueous acetone at 45 °C; conversely, α,α′-dihalo ketones were formed with pure water as the sole solvent at room temperature.
Silica gel catalyzed α-bromination of ketones using N-bromosuccinimide: An easy and rapid method
Mohan Reddy, Bodireddy,Venkata Ramana Kumar, Velpula,Chinna Gangi Reddy, Nallagondu,Mahender Rao, Siripragada
, p. 179 - 182 (2014/02/14)
An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide (NBS) catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time (5-20 min). Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.
Bronsted acidic ionic liquid accelerated halogenation of organic compounds with N-halosuccinimides (NXS)
Vrazic, Dejan,Jereb, Marjan,Laali, Kenneth K.,Stavber, Stojan
, p. 74 - 96 (2013/04/10)
The Bronsted-Acidic ionic liquid 1-methyl-3-(4-sulfobutyl) imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into a-halo and a,a-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of a-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO3H)][OTf] ionic liquid (IL-A) was successfully reused eight times in a representative monohalogenation reaction with no noticeable decrease in efficiency. An effective halogenation scale-up in this IL is also presented. The reactivity trend and the observed chemo- and regioselectiivities point to an ET process in these IL-promoted halofunctionalization reactions.
A tandem one-pot aqueous phase synthesis of thiazoles/selenazoles
Madhav,Narayana Murthy,Anil Kumar,Ramesh,Nageswar
experimental part, p. 3835 - 3838 (2012/08/14)
The first ever tandem one-pot synthetic protocol for the synthesis of thiazoles/selenazoles from alkynes via the formation of 2,2-dibromo-1- phenylethanone is reported. The reaction is catalyzed by β-cyclodextrin in aqueous medium and resulted in good yields.
Synthesis of dibromo ketones by the reaction of the environmentally benign H2O2-HBr system with oximes
Terentev, Alexander O.,Krylov, Igor B.,Vil, Vera A.,Pastukhova, Zhanna Yu.,Fastov, Sergey A.,Nikishin, Gennady I.
experimental part, p. 360 - 367 (2012/08/08)
It was found that oximes undergo deoximation in the presence of the H2O2aq-HBraq system to form ketones and bromo ketones. This reaction provided the basis for the synthesis of dibromo ketones in yields varying from 40% to 94%. This method is environmentally friendly, sustainable, and easy to perform. The results of this investigation extend the potential of the use of oximes for the protection of carbonyl group, thus offering the ability to perform not only conventional deoximation but also the subsequent bromination of ketones. The reaction is easily scaled up and dibromo ketones can be prepared in gram amounts. Versita Sp. z o.o.
