Comparative study of the vicinal functionalization of olefins with 2:1 bromide/bromate and iodide/iodate reagents
作者:Manoj K. Agrawal、Subbarayappa Adimurthy、Bishwajit Ganguly、Pushpito K. Ghosh
DOI:10.1016/j.tet.2009.01.095
日期:2009.4
halohydrins, halo methyl ethers, and halo acetates from olefins using 2:1 Br−/BrO3− and I−/IO3− reagents. In many cases both reagents afforded products selectively in high yields. The highest halogen atom efficiencies attained were 97% and 93% for Br−/BrO3− and I−/IO3−, respectively. Of the two reagents, I−/IO3− was established to be the preferred reagent for vicinal functionalization of linear alkenes and
BBr<sub>3</sub>-Assisted Preparation of Aromatic Alkyl Bromides from Lignin and Lignin Model Compounds
作者:Xuan Li、Jianghua He、Yuetao Zhang
DOI:10.1021/acs.joc.8b01628
日期:2018.9.21
important organic synthesis reagents, aromatic alkylbromides, in high to excellent yields (up to 98%). Preliminary studies also highlight the prospect of this method for the effective cleavage of different types of C–O bonds in real lignin. A total 14 wt % yield of aromatic alkylbromide, 4-(1,2-dibromo-3-hydroxypropyl)benzene-1,2-diol (10), has been obtained from an extracted lignin through this method
A highly diastereoselective pyrrolidine-promoted dibromination of alkenes by combination of NBS and succinimide is presented. The pyrrolidine-mediated dibromination of alkenes is higly anti-selective and gives the corresponding products in moderate to high yields and up to >25:1 dr.
Regio- and stereoselective hydroxybromination and dibromination of olefins using ammonium bromide and oxone®
作者:Arun Kumar Macharla、Rohitha Chozhiyath Nappunni、Narender Nama
DOI:10.1016/j.tetlet.2012.01.026
日期:2012.3
synthesis of vicinal bromohydrins and dibromides fromolefins is presented. Various olefins are regio- and stereoselectively hydroxybrominated and dibrominated with anti fashion, following Markonikov’s rule, using eco-friendly, non-toxic, and stable reagents such as NH4Br and oxone® in CH3CN/H2O (1:1) and CH3CN without employing catalyst in moderate to excellent yields. Bromohydrins are formed instantaneously
Catalytic Enantioselective Dihalogenation and the Selective Synthesis of (−)-Deschloromytilipin A and (−)-Danicalipin A
作者:Matthew L. Landry、Dennis X. Hu、Grace M. McKenna、Noah Z. Burns
DOI:10.1021/jacs.6b01643
日期:2016.4.20
A titanium-based catalytic enantioselective dichlorination of simple allylic alcohols is described. This dichlorination reaction provides stereoselective access to all common dichloroalcohol building blocks used in syntheses of chlorosulfolipid natural products. An enantioselectivesynthesis of ent-(-)-deschloromytilipin A and a concise, eight-step synthesis of ent-(-)-danicalipin A are executed and
描述了简单烯丙醇的钛基催化对映选择性二氯化。这种二氯化反应提供了对用于合成氯硫脂天然产物的所有常见二氯醇构建块的立体选择性访问。执行对映选择性合成 ent-(-)-deschloromytilipin A 和简洁的八步合成 ent-(-)-danicalipin A,并采用二氯化反应作为第一步。报道了该系统扩展到对映选择性二溴化及其在合成与溴硫脂相关的五溴化物立体阵列中的用途。所描述的二氯化和二溴化反应能够在复杂的环境中进行非对映控制,允许对多卤化立体六联体的天然和非天然非对映异构体进行 X 射线晶体结构分析。