Radical Heteroarylalkylation of Alkenes via
<scp>Three‐Component Docking‐Migration</scp>
Thioetherification Cascade
作者:Tao Niu、Jige Liu、Xinxin Wu、Chen Zhu
DOI:10.1002/cjoc.202000088
日期:2020.8
A novel, rational‐designed approach to access various heteroaryl‐substituted alkyl thioethers was developed via docking‐migration cascade process. By utilizing three components involving alkene, dual‐function reagent, and thioetherificating reagent, radical heteroarylalkylation of alkenes followed by thiolation of the alkyl radical intermediates proceeded smoothly, manifesting well compatibility of
METHOD FOR PREPARING TETRAZOLE METHANESULFONIC ACID SALTS, AND NOVEL COMPOUND USED IN SAME
申请人:Bang Keuk Chan
公开号:US20120330020A1
公开(公告)日:2012-12-27
According to the present invention, a method for preparing tetrazole methanesulfonic acid salts comprises an acylation reaction using a novel 4-iodine-4H-chromene-2-carbothionic acid S-benzothiazole-2-yl ester. The method of the present invention can shorten a reaction time and improve safety as compared to conventional methods, and can prepare high-purity tetrazole methanesulfonic acid salts at a high yield rate without using a column chromatography method.
S-Alkylation en s�rie h�t�rocyclique par catalyse par transfert de phase: thioalkyl-2-thiazoles, thioalkyl-2-?-4-thiazolines et thioalkyl-2-benzothiazoles
作者:Henri J. M. Dou、Parina Hassanaly、Jacky Kister、Gaston Vernin、Jacques Metzger
DOI:10.1002/hlca.19780610842
日期:1978.12.13
S-Alkylation in heterocyclic serie by phase transfer catalysis: 2-alkylthiothiazoles, 2-alkylthio-Δ-4-thiazolines and 2-alkylthiobenzothiazoles
finds limited applications in fine chemical synthesis, resulting in molecules of modest complexity. Ethylene difunctionalization allows for the synthesis of much more complex chemicals, but it is rare and almost always relies on transition-metal catalysis. Herein, we report an unprecedented metal-free radical difunctionalization of ethylene through a functional group migration strategy. The use of sulfone-based
methods that address the selective formation of (Z)-olefins. In such cases, specific catalysts (e. g., cross-metathesis)3 or modified anion stabilizing groups (e. g., Still-Gennari modification of Horner-Wadsworth-Emmonsolefination)4 are utilized. The Peterson olefination,2g, 2h on the other hand, allows for the stereoselective formation of either (E) or (Z)-olefins from the same starting material by a
介绍 碳-碳键形成反应是有机合成化学中的关键连接反应。其中,不饱和键(特别是烯烃)的立体选择性形成具有重要意义,因为它们参与天然产物、生物活性化合物和材料的合成。目前,实现立体选择性连接烯化的两种常用方法是烯烃交叉复分解1和阴离子稳定试剂与醛或酮的偶联2(图 1)。这些方法通常在温和的反应条件下进行,对官能团表现出良好的耐受性,并且主要产生( E )-构型的烯烃。然而,解决( Z )-烯烃的选择性形成的方法有限。在这种情况下,使用特定的催化剂(例如交叉复分解)3或改性阴离子稳定基团(例如Horner-Wadsworth-Emmons烯化的Still-Gennari改性)4 。另一方面,Peterson 烯化(2g,2h)允许通过反应后处理(酸性与碱性)的简单改变,从相同的起始材料立体选择性地形成( E)或(Z )-烯烃。 5然而,即使在这种情况下,原位生成的加合物 (顺/反)的立体选择性也反映在烯化反应的最终立体化学结果中。