A New Tool To Guide Halofunctionalization Reactions: The Halenium Affinity (<i>HalA</i>) Scale
作者:Kumar Dilip Ashtekar、Nastaran Salehi Marzijarani、Arvind Jaganathan、Daniel Holmes、James E. Jackson、Babak Borhan
DOI:10.1021/ja506889c
日期:2014.9.24
previously unexplored parameter—halenium affinity (HalA)– as a quantitative descriptor of the bond strengths of various functional groups to halenium ions. The HalA scale ranks potential halenium ion acceptors based on their ability to stabilize a “free halenium ion”. Alkenes in particular but other Lewis bases as well, such as amines, amides, carbonyls, and ether oxygen atoms, etc., have been classified
我们引入了一个先前未探索的参数——铯亲和力(HalA)——作为各种官能团与铯离子键合强度的定量描述符。 HalA 等级根据潜在的铯离子受体稳定“游离铯离子”的能力对它们进行排名。特别是烯烃,以及其他路易斯碱,例如胺、酰胺、羰基和醚氧原子等,都已按照 HalA 等级进行分类。这种间接方法能够快速、直接地预测涉及具有多个亲核位点的卤官能化反应的系统的化学选择性。 HalA 计算本质上解释了微妙的电子和空间变化的影响,以及难以预测的嵌合效应和立体电子效应,提供了超越简单“化学直觉”的定量评估。这种理论与实验相结合的方法提供了一种预测和识别前所未有的反应的快捷方法。
Electrocatalytic Radical Dichlorination of Alkenes with Nucleophilic Chlorine Sources
作者:Niankai Fu、Gregory S. Sauer、Song Lin
DOI:10.1021/jacs.7b09388
日期:2017.11.1
alkenes with MgCl2 as the chlorine source. This method provides operationally simple, sustainable, and efficient access to a variety of vicinally dichlorinated compounds. In particular, alkenes with oxidatively labile functional groups, such as alcohols, aldehydes, sulfides, and amines, were transformed into the desired vicinal dichlorides with high chemoselectivity. Mechanistic data are consistent with
Catalytic Enantioselective Halolactonization of Enynes and Alkenes
作者:Wei Zhang、Na Liu、Casi M. Schienebeck、Kyle Decloux、Suqing Zheng、Jenny B. Werness、Weiping Tang
DOI:10.1002/chem.201103809
日期:2012.6.4
developed for the enantioselectivehalolactonization of (Z)‐1,3‐enynes and 1,1‐disubstituted alkenes. In the case of 1,3‐enynes, the carboxylate nucleophile and halogen electrophile were added to the conjugated π‐system from the same face. Up to 99 % ee was achieved for the 1,4‐syn‐bromolactonization of conjugated (Z)‐1,3‐enynes. Based on the results from the enynehalolactonization, a second generation
Indium chloride mediated chlorolactonization: construction of chlorinated lactone fragments
作者:Hideki Abe、Naoki Fukazawa、Toyoharu Kobayashi、Hisanaka Ito
DOI:10.1016/j.tet.2013.01.072
日期:2013.3
Chlorolactonization of unsaturated acids with chloramine-T catalyzed by indium chloride as a Lewis acid was demonstrated. This is a new synthetic methodology for the construction of chlorinated lactone frameworks from unsaturated acids. (C) 2013 Elsevier Ltd. All rights reserved.