Photo-Induced Sonogashira C-C Coupling Reaction Catalyzed by Simple Copper(I) Chloride Salt at Room Temperature
Photo-Induced Sonogashira C-C Coupling Reaction Catalyzed by Simple Copper(I) Chloride Salt at Room Temperature
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DOI：
10.1002/adsc.201200683
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发表时间：
2012-12-01
影响因子：
5.4
通讯作者：
Hwang, Kuo Chu
中科院分区：
文献类型：
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作者：
Sagadevan, Arunachalam;Hwang, Kuo Chu
传统的热Sonogashira C？C偶联反应需要使用钯催化剂和大量配体。尽管有一些报道描述了在Sonogashira反应中使用廉价的金属催化剂，例如铜（Cu）、铁（Fe）和镍（Ni）来替代钯（Pd），但后来有人质疑所观察到的效果是由于反应中使用的试剂中存在的ppb水平的Pd污染。在此，我们报告了简单的氯化铜（I）（CuCl）盐，在没有Pd和配体的情况下，可以催化Sonogashira反应，在室温下，在蓝色LED光照射下，高产率（80 - 99%）。对照实验表明，当使用氯化钯（II）（PdCl 2）代替CuCl作为催化剂时，没有形成交叉偶联产物。研究了一系列富电子和贫电子取代芳基卤（溴和碘）以及芳基和烷基乙炔的反应，并讨论了反应机理。
The conventional thermal Sonogashira C?C coupling reaction requires the use of a palladium catalyst and a large amount of ligands. Although there were a few reports describing the use of inexpensive metal catalysts, such as, copper (Cu), iron (Fe), and nickel (Ni), for replacement of palladium (Pd) in the Sonogashira reactions, it was later questioned that the observed effects were due to ppb levels contamination of Pd present in the reagents used in the reactions. Herein, we report that simple copper(I) chloride (CuCl) salt, in the absence of Pd and ligands, can catalyze the Sonogashira reaction with high yields (8099%) under blue LED light irradiation at room temperature. Control experiments show that no cross-coupling product was formed, when palladium(II) chloride (PdCl2) was used to replace CuCl as a catalyst. A series of electron-rich and electron-poor substituted aryl halides (bromides and iodides) as well as aryl- and alkylacetylenes are examined and the reaction mechanism is discussed.