Herein, synthesis of benzothiazoles via decarboxylative cross‐coupling between α‐keto acids and 2‐aminothiophenols under blue LED irradiation without using any photocatalyst or metal at room temperature is described. The formation of benzothiazole is driven by the EDA (electron donor‐acceptor) complex formed between α‐keto acid and 2‐aminothiophenol. This methodology gives easy access to 2‐substituted
Cross-Dehydrogenative Coupling of Heterocyclic Scaffolds with Unfunctionalized Aroyl Surrogates by Palladium(II) Catalyzed C(sp<sup>2</sup>)-H Aroylation through Organocatalytic Dioxygen Activation
作者:Bhavin V. Pipaliya、Asit K. Chakraborti
DOI:10.1021/acs.joc.7b00226
日期:2017.4.7
carbonyl group of aryl aldehyde and the aryl methane. However, the ease of availability of aryl methanes makes them the most attractive as an aroyl source. A time dependent selective mono- and bis-aroylation can be achieved. The 1,3-diarylpyrimidines exhibited regioselective aroylation of the 2-phenyl moiety irrespective of the absence or presence of any substitutent (electronwithdrawing or electron donating)
通过NHPI的双氧激活,在Pd(II)催化的C(sp 2)-H活化过程中,生物相关的杂环支架与芳基甲烷的芳基化反应进行了脱氢偶联。质谱和基于1 H NMR的动力学同位素效应研究表明,CH键的活化是决定速率的步骤。自由基清除实验表明存在自由基途径。在1等分试样的反应混合物的1 H NMR和用2-氨基硫代苯酚原位捕集揭示芳基甲烷的需氧氧化过程中醛的形成。该反应对于芳酰基源和包括苯并噻唑,苯并恶唑,吡啶,喹喔啉,嘧啶和偶氮芳烃的导向基团的不同变化具有广泛的范围。发现苄基亚甲基部分是芳酰基碳的来源,最优选苄基醚部分,其次是芳基醛和芳基甲烷的羰基。但是,芳基甲烷的易得性使其成为芳酰基源最具吸引力。可以实现时间依赖性的选择性单-和双-芳基化。1 3-二芳基嘧啶表现出2-苯基部分的区域选择性芳酰基化,而与3-苯基部分中是否存在任何取代基(吸电子或供电子)无关。对于不对称的偶氮芳烃,在带有取代基的苯基部分中发生选择性芳酰基化。
Synthesis of 2-Substituted Benzothiazoles by Visible Light-Driven Photoredox Catalysis
作者:Chunghyeon Yu、Kyungyub Lee、Youngmin You、Eun Jin Cho
DOI:10.1002/adsc.201300376
日期:2013.5.17
An efficient method for synthesis of the widely applicable 2‐substituted benzothiazoles has been developed. The process requires only 0.1 mol% [Ru(bpy)3Cl2], O2, and visible light irradiation with substrates: 2‐aminothiophenol and a variety of aldehydes. We established an oxidative quenching of the photoredox catalyst as being the key process in this photoelectrocatalytic cycle.
Elemental sulfur mediated cyclization via redox strategy: Synthesis of benzothiazoles from o -chloronitrobenzenes and benzyl chlorides
作者:Xin Wang、Dazhuang Miao、Xiaotong Li、Renhe Hu、Zhao Yang、Ren Gu、Shiqing Han
DOI:10.1016/j.tet.2017.07.013
日期:2017.8
A novel metal-free synthesis of 2-substituted benzothiazoles from easily available o-chloronitrobenzenes and benzyl chlorides using elementalsulfur as traceless oxidizing agent has been developed. The protocol provides a simple, efficient, and atom-economic way to access to benzothiazoles in moderate to excellent yields. And the approach exhibited good functional group tolerance.
ZnO-NPs catalyzed condensation of 2-aminothiophenol and aryl/alkyl nitriles: Efficient green synthesis of 2-substituted benzothiazoles
作者:Kiran D. Dhawale、Ajit P. Ingale、Sandeep V. Shinde、Nitin M. Thorat、Limbraj R. Patil
DOI:10.1080/00397911.2021.1894577
日期:——
Abstract The synthesis of 2-substituted benzothiazoles has been described using ZnO-nanoparticles as a catalyst. The condensation of 2-aminothiophenol and aryl/alkyl nitriles resulted in the formation of various 2-substituted benzothiazoles under solvent-free reaction conditions. The library of 2-substituted benzothiazoles has been synthesized in good to excellent yield. The reaction has shown a wide