Carbon Halide Bond Activation of Benzyl Chloride and Benzyl Bromide Using An NHC‐Stabilized Nickel(0) Complex
Carbon Halide Bond Activation of Benzyl Chloride and Benzyl Bromide Using An NHC‐Stabilized Nickel(0) Complex
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DOI：
10.1002/zaac.201100162
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发表时间：
2011-10
期刊：
影响因子：
--
通讯作者：
T. Zell;U. Radius
中科院分区：
文献类型：
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作者：
T. Zell;U. Radius
本文报道了nhc稳定镍配合物作为催化剂在烷基卤化物Suzuki-Miyaura交叉偶联反应中的首次应用。由氯化苄和溴化苄与双核配合物[Ni2(iPr2Im)4(COD)](1)反应制备了反式配合物[Ni(iPr2Im)2(X)(CH2Ph)] （X = Cl 2和br3）。这些化合物通过元素分析、红外光谱、多核磁共振光谱和x射线晶体学进行了充分的表征。在这些化学计量氧化加成反应的基础上，进行了催化Suzuki-Miyaura交叉偶联反应。配合物1是氯化苄与苯硼酸Suzuki-Miyaura交叉偶联反应的有效催化剂。以3等量苯硼酸、3等量氟化铯和1.22 mol-% [Ni2(iPr2Im)4(COD)](1)为催化剂，经2小时反应，实现了氯化苄高选择性定量转化为交叉偶联产物二苯甲烷。
A first example of the application of an NHC-stabilized nickel complex as a catalyst in Suzuki–Miyaura cross-coupling reactions of alkyl halides is reported. The complexes trans-[Ni(iPr2Im)2(X)(CH2Ph)] (X = Cl 2 and Br 3) were prepared from the reactions of benzyl chloride and benzyl bromide and the dinuclear complex [Ni2(iPr2Im)4(COD)] (1). These compounds were fully characterized by elemental analysis, IR spectroscopy, multinuclear NMR spectroscopy, and X-ray crystallography. Based on these stoichiometric oxidative addition reactions catalytic Suzuki–Miyaura cross-coupling reactions have been performed. Complex 1 is an effective catalyst for the Suzuki–Miyaura cross-coupling reaction of benzyl chloride and phenylboronic acid. Quantitative conversion of benzyl chloride with a high selectivity to the cross-coupling product diphenylmethane was achieved after two hours reaction time using three equivalents phenylboronic acid, three equivalents cesium fluoride and 1.22 mol-% [Ni2(iPr2Im)4(COD)] (1) as a catalyst.