在本文中,我们描述了三氟甲磺酸银/对甲苯磺酸共催化合成17个异香豆素和两个由2-炔基苯甲酸酯和3-炔基噻吩-2-羧酸酯组成的噻吩并[2,3 - c ]吡喃-7-,分别。反应在温和的反应条件下和低的催化剂载量下以绝对的区域选择性进行,以良好至极好的收率提供所需的产物。提出了一种可能的反应机理,并得到了同位素交换试验,1 H NMR研究和特别实验的支持。
Dual gold/photoredox-catalyzed C(sp)–H arylation of terminal alkynes with diazonium salts
作者:Adrian Tlahuext-Aca、Matthew N. Hopkinson、Basudev Sahoo、Frank Glorius
DOI:10.1039/c5sc02583d
日期:——
The arylation of alkyl and aromatic terminal alkynes by a dual gold/photoredoxcatalytic system is described. Using aryldiazonium salts as readily available aryl sources, a range of diversely-functionalized arylalkynes could be synthesized under mild, base-free reaction conditions using visible light from simple household sources or even sunlight. This process, which exhibits a broad scope and functional
描述了金/光氧化还原双催化系统对烷基和芳族末端炔烃的芳基化。使用芳基重氮盐作为容易获得的芳基源,可以使用来自简单家庭来源的可见光甚至阳光,在温和、无碱的反应条件下合成一系列不同官能化的芳基炔。该过程表现出广泛的范围和官能团耐受性,将双金/光氧化还原催化的转化范围扩大到涉及 C-H 键功能化的转化范围,并证明了该概念在以下条件下获得 Au I / Au III氧化还原化学的潜力:温和的氧化还原中性条件。
Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily
A non‐oxidant and metal‐free strategy for synthesizing iso‐coumarin by using a continuous electrochemical microreactor to initiate an oxidative cyclization reaction of o‐(1‐alkynyl) benzoate and radicals. This efficient and clean continuous electrosynthesis method not only avoids the complicated gas protection operation and production of by‐products in the batch processes, but also help to overcome
Facile synthesis of sulfenyl-substituted isocoumarins, heterocycle-fused pyrones and 3-(inden-1-ylidene)isobenzofuranones by FeCl3-promoted regioselective annulation of o-(1-alkynyl)benzoates and o-(1-alkynyl)heterocyclic carboxylates with disulfides
作者:Zhen Li、Jianquan Hong、Linhong Weng、Xigeng Zhou
DOI:10.1016/j.tet.2011.12.003
日期:2012.2
Reported herein is the FeCl3-promoted intermolecular sulfoesterification of o-(1-alkynyl)benzoates with disulfides, which provides a convenient and efficient method for synthesis of 4-sulfenylisocoumarins. Various functional groups such as methoxy, halides, ester, cyano and silicon groups in the substrates are tolerated, and heterocycle-fused chalcogenylpyrones are also successfully achieved directly
excellent yields starting from 2-alkynylbenzoates and arenediazonium salts. The strategy involves a domino arylation/oxo-cyclization catalysed by a dual photoredox/goldcatalytic system. The reactions run under mild conditions at room temperature in wet acetonitrile under irradiation with a blue-LED lamp, in the presence of a cationic gold catalyst and a cheap organic photocatalyst. The scope is quite broad
从 2-炔基苯甲酸酯和芳烃重氮盐开始,已经以良好至优异的产率合成了几种异香豆素。该策略涉及由双光氧化还原/金催化系统催化的多米诺芳基化/氧合环化。该反应在温和条件下室温下在湿乙腈中进行,在蓝色 LED 灯照射下,在阳离子金催化剂和廉价有机光催化剂存在下进行。范围很广,允许制备在 3 位和 4 位不同的二取代的异香豆素。提出了一种合理的反应机理。