Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C–H Thiolation via Reverse Hydrogen Atom Transfer
作者:Ze-Ming Xu、Hong-Xi Li、David James Young、Da-Liang Zhu、Hai-Yan Li、Jian-Ping Lang
DOI:10.1021/acs.orglett.8b03679
日期:2019.1.4
This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidineN-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
for transamidation of thioamides by N−C(S) transacylation is reported. This process exploits the concept of site-selective N-tert-butoxycarbonyl activation, resulting in ground-state-destabilization of thioamides. The study establishes a powerful direction to the development of new molecules in chemistry and biology by rational modification of nN→π*C=S resonance of the thioamide bond.
报道了第一种通过 NC(S) 转酰基作用对硫代酰胺进行转酰胺基作用的通用、温和且高度化学选择性的方法。该过程利用了位点选择性 N-叔丁氧羰基活化的概念,导致硫代酰胺的基态不稳定。该研究通过对硫代酰胺键的n N →π* C=S共振进行合理修饰,为化学和生物学新分子的发展奠定了有力的方向。
One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides
The development of novel and efficient synthesismethods for 2-substituted benzazole derivatives is of interest as they are biologically active substances. Herein, a simple method for the synthesis of 2-aryl- and 2-alkyl-substituted benzazoles is described. The reaction of 2-aminophenols with thioamides at 60 °C in the presence of triphenylbismuth dichloride in 1,2-dichloroethane as a promoter afforded
2-取代苯并唑衍生物是具有生物活性的物质,因此开发新颖且有效的合成方法引起了人们的兴趣。本文描述了合成 2-芳基-和 2-烷基-取代的苯并唑的简单方法。 2-氨基苯酚与硫代酰胺在 60 °C 下,在二氯化三苯基铋的存在下,在 1,2-二氯乙烷中作为促进剂,在温和的反应条件下以中等至优异的收率提供各种 2-芳基-和 2-烷基苯并恶唑。该方法也可用于苯并咪唑和苯并噻唑的合成。本研究首次使用三苯基二氯化铋通过硫代酰胺经脱硫和氯化生产苯甲亚胺酰氯,及其在2-取代苯并唑合成中的应用。
The Role of Base in Reaction Performance of Photochemical Synthesis of Thiazoles: An Integrated Theoretical and Experimental Study
作者:Jiaxin Xu、Xiaoyu Ye、Zongchao Lv、Yi‐Hung Chen、Xiang Simon Wang
DOI:10.1002/chem.202304279
日期:——
testing. Feature analysis is conducted through the model interpretation process, enabling further exploration into the reaction mechanisms. We then chose two substrates of distinct structures and verified the predictions through experimental benchwork. This represents a novel reaction with different bases.