21770-48-9Relevant academic research and scientific papers
Catalyst-Free 1,2-Dibromination of Alkenes Using 1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) as a Bromine Source
Wang, Lei,Zhai, Lele,Chen, Jinyan,Gong, Yulin,Wang, Peng,Li, Huilin,She, Xuegong
supporting information, p. 3177 - 3183 (2022/02/23)
A direct 1,2-dibromination method of alkenes is realized using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as a bromine source. This reaction proceeds under mild reaction conditions without the use of a catalyst and an external oxidant. Various sorts of alkene substrates are transformed into the corresponding 1,2-dibrominated products in good to excellent yields with broad substrate scope and exclusive diastereoselectivity. This method offers a green and practical approach to synthesize vicinal dibromide compounds.
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
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.
Enantiospecific on-water bromination: A mild and efficient protocol for the preparation of alkyl bromides
Alletto, Francesco,Adamo, Mauro F. A.
supporting information, p. 8692 - 8698 (2020/12/29)
Herein we report the first example of an on-water enantiospecific synthesis of alkyl bromides. This procedure allowed the conversion of secondary activated alkyl sulphides to benzylic alkyl bromides, which were obtained in 80-99% yields. The reaction carried out on enantio-pure sulphides provided the corresponding bromides in high yields and enantioselectivity (up to 92% ee; 94% es) at room temperature. The on-water conditions reduced significantly the reaction times compared to similar procedures run in organic media. The condition identified made use of no solvent, required no temperature control and produced a smooth organic phase easily separated for further synthetic use on a multigram-scale without the need for any organic extraction. Therefore, the present constitutes the most operationally simple and environmentally benign approach to a class of much sought organic intermediates. This journal is
One-pot and regioselective synthesis of functionalized γ-lactams via a metal-free sequential Ugi 4CR/Intramolecular 5-exo-dig cyclization reaction
Yan, Yan-Mei,Wang, Meng-Liang,Liu, Yu-Long,He, Ying-Chun
, (2020/07/24)
A new one-pot and regioselective synthesis of functionalized γ-lactams by a metal-free Ugi 4CR/intramolecular 5-exo-dig cyclization sequence under mild conditions has been developed. The reaction of propenoic acids, aldehydes, amines, and isocyanides produced γ-lactams regioselectively in 72–89percent yields via sequential Ugi 4CR/intramolecular 5-exo-dig cyclization reaction in the presence of Cs2CO3.
Preparation method of 1-aryl-1,2-dibromoethane
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Paragraph 0022-0023, (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.
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.
Synthesis and antibacterial evaluation of novel 11-O-aralkylcarbamoyl-3-O-descladinosylclarithromycin derivatives
Jia, Li,Wang, Yinhu,Wang, Yanxia,Qin, Yinhui,Hu, Chaoyu,Sheng, Juzheng,Ma, Shutao
supporting information, p. 2471 - 2476 (2018/06/06)
A series of novel 11-O-aralkylcarbamoyl-3-O-descladinosylclarithromycin derivatives were designed, synthesized and evaluated for their in vitro antibacterial activity. The results showed that the majority of the target compounds displayed potent activity against erythromycin-susceptible S. pyogenes, erythromycin-resistant S. pneumoniae A22072 expressing the mef gene and S. pneumoniae AB11 expressing the mef and erm genes. Besides, most of the target compounds exhibited moderate activity against erythromycin-susceptible S. aureus ATCC25923 and B. subtilis ATCC9372. In particular, compounds 11a, 11b, 11c, 11e, 11f and 11h were found to exert favorable antibacterial activity against erythromycin-susceptible S. pyogenes with the MIC values of 0.015–0.125 μg/mL. Furthermore, compounds 10e, 11a, 11b and 11c showed superior activity against erythromycin-resistant S. pneumoniae A22072 with the MIC values of 0.25–0.5 μg/mL. Additionally, compound 11c was the most effective against all the erythromycin-resistant S. pneumoniae strains (A22072, B1 and AB11), exhibiting 8-, 8- and 32-fold more potent activity than clarithromycin, respectively.
Method for synthesizing alpha,beta-dibromide
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Paragraph 0048; 0049; 0050, (2018/04/01)
The invention discloses a method for synthesizing alpha,beta-dibromide. The method is characterized in that a styrene compound as shown in the formula I is taken as a raw material, Zn-Al hydrotalciteZnAl-BrO3-LDHs of a bromate intercalation is taken as
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.
