Synthesis and characterization of the syn-bromonium ion of 4-equ chloroadamantylidenadamantane, towards a chiral bromination reagent

Synthesis and characterization of the stable bromonium ion of 4-equ-chloroadamantylideneadamantane is described. ¹³C and ¹H NMR spectroscopy reveal preferred formation of the syn-isomer, which might be used as chiral bromination reagent using resolved starting material.     

Practical and regioselective brominations of aromatic compounds using tetrabutylammonium peroxydisulfate

Direct bromination of wide range of aromatic compounds substituted with electron donating groups such as methoxy, hydroxy, or amino groups have been achieved with high regioselectivity by the reaction with Br₂ in the presence of tetrabutylammonium peroxydisulfate 1 under mild conditions in acetonitrile in excellent yields. The use of lithium bromide as a bromination reagent afforded high yields of monobromo compounds with complete regioselectivity under neutral and mild reaction conditions in acetonitrile.     

黄酮类化合物研究(ⅩⅣ)——溴代异黄酮合成中的脱溴反应

我们曾报道2-溴间苯二酚在BF_3催化下酰化时的脱溴现象。本文在以下述反应制备6-溴代异黄酮时发现4-溴间苯二酚脱溴现象更为显著。     

Computational studies of benzyl-substituted halonium ions

Density functional computations were carried out whose objectives were to quantify the interactions of chlorine and bromine with neighboring cationic centers in a series of 1-aryl-2-haloethyl cations. Analysis of structural changes and bonding interactions gave rise to linear correlations with σ⁺ values of the aryl substituents. Electron-donating groups diminished bridging and electron-withdrawing groups gave rise to stronger bridging.     

溴鎓离子的结构解析

溴鎓离子是烯烃与溴加成历程中的环状中间体,详细解析其结构对理解不同烯烃与溴的加成历程以及判断加成产物都大有裨益。目前,国内外的教材还没有关于溴鎓离子结构的详细介绍,本文将对溴鎓离子三元环中各原子的杂化方式和电荷分布及后续的亲核取代历程等方面进行分析,以期为有机化学教材提供适当的补充。