One-pot approach for the synthesis of 2-aryl benzothiazoles via a two-component coupling of gem-dibromomethylarenes and o-aminothiophenols
摘要:
One-pot synthesis of 2-aryl benzothiazoles from gem-dibromomethylarenes using 2-aminoarylthiols is described. Benzothiazoles were obtained in high chemical yields under mild conditions. This transformation would facilitate synthesis by short reaction times, large-scale synthesis, easy and quick isolation of the products, which are the main advantages of this procedure. (C) 2011 Published by Elsevier Ltd.
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.
Visible-light-induced tandem reaction of o -aminothiophenols and alcohols to benzothiazoles over Fe-based MOFs: Influence of the structure elucidated by transient absorption spectroscopy
作者:Dengke Wang、Josep Albero、Hermenegildo García、Zhaohui Li
DOI:10.1016/j.jcat.2017.01.014
日期:2017.5
contrast to MIL-68(Fe). This study not only provides an economical, sustainable, and thus green process for the production of 2-substitutedbenzothiazoles, but also illustrates the potential of using transient absorption spectroscopy as an important tool for understanding the photophysics of MOFs, which are believed to show great potential as multifunctional catalysts for light-induced organic transformations
Ceric Ammonium Nitrate (CAN) Promoted Pd<sup>II</sup>-Catalyzed Substrate-Directed<i>o</i>-Benzoxylation and Decarboxylative<i>o</i>-Aroylation
作者:Sourav Kumar Santra、Arghya Banerjee、Nilufa Khatun、Bhisma K. Patel
DOI:10.1002/ejoc.201403367
日期:2015.1
Inexpensive cericammoniumnitrate (CAN) is an efficient oxidant for the Pd-catalyzed substrate-directed o-benzoxylation and decarboxylative o-aroylation processes. In the presence of CAN, the reaction of directing arenes with carboxylic acids resulted in o-benzoxylated products, whereas a decarboxylative o-aroylation occurred by using α-keto acids, which led to the formation of o-aroylation products
廉价的硝酸铈铵 (CAN) 是 Pd 催化的底物导向邻苯甲氧基化和脱羧邻芳酰化过程的有效氧化剂。在 CAN 存在下,定向芳烃与羧酸反应生成邻苯甲酰化产物,而使用 α-酮酸发生脱羧邻芳酰化,从而形成邻芳酰化产物。
A Highly Efficient Palladium/Copper Cocatalytic System for Direct Arylation of Heteroarenes: An Unexpected Effect of Cu(Xantphos)I
作者:Jinkun Huang、Johann Chan、Ying Chen、Christopher J. Borths、Kyle D. Baucom、Robert D. Larsen、Margaret M. Faul
DOI:10.1021/ja100354j
日期:2010.3.24
Heteroarenes are important structural moieties in many chemical industry fields. A highly efficient Pd/Cu-catalyzed C-H arylation method for a range of heterocycles has been discovered. It was found that the key to the success of this transformation is a combination of a palladiumcatalyst and a well-defined copper cocatalyst. The efficiency and lowloadings of catalyst (0.25 mol %) and cocatalyst