Maity Ayan, Sulicz Amanda N, Deligonul Nihal, Zeller Matthias, Hunter Allen D, Gray Thomas G
Department of Chemistry , Case Western Reserve University , 10900 Euclid Avenue , Cleveland , Ohio 44106 , USA . Email:
Department of Chemistry , Youngstown State University , 1 University Plaza , Youngstown , Ohio 44555 , USA.
Chem Sci. 2015 Feb 1;6(2):981-986. doi: 10.1039/c4sc02148g. Epub 2014 Nov 6.
Gold(iii) is prominent in catalysis, but its organometallic chemistry continues to be restricted by synthesis. Metal-carbon bond formation often relies on organometallic complexes of electropositive elements, including lithium and magnesium. The redox potential of gold(iii) interferes with reactions of these classic reagents. Resort to toxic metals is common, including reagents based on mercury and thallium. We report that the palladium-catalyzed Suzuki-Miyaura coupling of arylboronic acids extends to cyclometalated gold(iii) chlorides. Both monoarylation and diarylation are achieved. We propose a mechanism where oxidative addition to palladium with rearrangement at gold(iii) fixes the stereochemistry of monoarylated intermediates. Singly arylated species form as thermodynamic isomers. These entities then go on to form diarylated complexes. Reactions proceed at room temperature, and the products are stable to air, moisture, and chromatography.
金（III）在催化领域表现突出，但其有机金属化学仍受合成方面的限制。金属 - 碳键的形成通常依赖于包括锂和镁在内的电正性元素的有机金属配合物。金（III）的氧化还原电位会干扰这些经典试剂的反应。常用有毒金属试剂，包括基于汞和铊的试剂。我们报道钯催化的芳基硼酸的铃木 - 宫浦偶联反应可扩展至环金属化金（III）氯化物。单芳基化和双芳基化反应均能实现。我们提出了一种机理，即钯的氧化加成以及金（III）处的重排确定了单芳基化中间体的立体化学。单芳基化物种以热力学异构体形式形成。这些实体随后继续形成双芳基化配合物。反应在室温下进行，产物对空气、水分和色谱分析稳定。
