我们报告了在化学计量的CuI,2,2'-联吡啶存在下,通过铜介导的需氧C–H键活化,通过苯并噻唑与芳基或烷基硫醇的直接硫醇化反应,合成了一系列芳基或烷基取代的2-巯基苯并噻唑和Na 2 CO 3。我们还表明该方法可以扩展到噻唑,苯并咪唑和吲哚底物。此外,我们目前对Cu(I)介导的直接硫醇化反应的详细机理研究。计算研究和实验结果均表明,铜-硫醇盐络合物[(L)Cu(SR)](L:基于氮的双齿配体,例如2,2'-联吡啶; R:芳基或烷基)是第一反应性负责观察到的有机转化的中间体。此外,我们的计算研究表明,基于氢原子提取途径的逐步反应机理,比包括β-氢化物消除,单电子转移,氢原子转移,氧化加/还原消除和σ在内的许多其他可能途径在能量上更可行。键易位。
We describe herein a convenient strategy for the construction of C,C-glycoside building blocks via the intermediacy of tertiary pseudoanomeric radicals. Application of an iron-mediated hydrogen atom transfer/Michael–Giese coupling enables the anomeric quaternization of readily available exo-glycals with good to complete stereocontrol in the pyranose and furanose series. Carefully optimized conditions
Novel 3-Methyl-2-alkylthio Benzothiazolyl-Based Ionic Liquids: Synthesis, Characterization, and Antibiotic Activity
作者:Teng Zhang、Hao He、Jun Du、Zhi He、Shun Yao
DOI:10.3390/molecules23082011
日期:——
first time. After structural identification, their melting point, solubility, and thermostability together with antibiotic activity were determined successively. As a result, 3-methyl-2-alkylthio benzothiazolyl p-toluene sulfonate was found to have the highest antibacterial activity among the three series of ILs. Meanwhile, it has a good solubility in water as well. On the basis of comprehensive comparison
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。
UENO, YOSHIO;KOJIMA, AKIHIKO;OKAWARA, MAKOTO, CHEM. LETT., 1984, N 12, 2125-2128