5837-69-4Relevant articles and documents
Zwitterion-Catalyzed Intermolecular Bromoesterifications
Ng, Wing-Hin,Hu, Rong-Bin,Lam, Ying-Pong,Yeung, Ying-Yeung
, p. 5572 - 5576 (2020)
Intermolecular haloesterification is an important class of transformations. The resulting products are valuable building blocks. However, it is often necessary to use super-stoichiometric amount of acid in order to compensate the low reactivity. Herein, we report a zwitterion-catalyzed intermolecular bromoesterification using acid and olefin in an equimolar ratio. Mechanistic study revealed that the charge pair in the zwitterion works synergistically in activating both NBS and carboxylic acid.
Method for synthesizing beta-bromoacetate compounds
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Paragraph 0029; 0030; 0032; 0033; 0035; 0036; 0038; 0039, (2019/01/22)
The invention discloses a method for synthesizing beta-bromoacetate compounds. The method comprises the following steps: reacting in an organic solvent at a temperature of 15-60 DEG C for 1-6 hours bytaking styrene compounds shown as a formula I as raw ma
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.).