Strong Lewis Acids of Air-Stable Metallocene Bis(perfluorooctanesulfonate)s as High-Efficiency Catalysts for Carbonyl-Group Transformation Reactions
Strong Lewis Acids of Air-Stable Metallocene Bis(perfluorooctanesulfonate)s as High-Efficiency Catalysts for Carbonyl-Group Transformation Reactions
复制标题
空气稳定的茂金属双（全氟辛烷磺酸）的强路易斯酸作为羰基转化反应的高效催化剂
DOI：
10.1002/chem.201103874
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发表时间：
2012-05-01
影响因子：
4.3
通讯作者：
Yin, Shuangfeng
中科院分区：
文献类型：
--
作者：
Qiu, Renhua;Xu, Xinhua;Yin, Shuangfeng
通过[M(Cp)2]Cl2反应合成了空气稳定的茂金属双(全氟辛烷磺酸)s强路易斯酸[M(Cp)2][OSO2C8F17]2中心点nH2O中心点THF(M=Zr(2a中心点3H2O中心点THF)、M=Ti(2b中心点2H2O中心点THF))) （M=Zr (1a)，M=Ti (1b)）与 nBuLi 和 C8F17SO3H（2 当量）或与 C8F17SO3Ag（2 当量）。这些复合物的水合物数 (n) 是可变的，根据条件从 0 变化到 4。与众所周知的茂金属三氟甲磺酸酯相比，这些配合物在露天一年内没有发生任何变化。热重差示扫描量热法（TG-DSC）分析表明2a和2b分别在300和180℃下热稳定。这些配合物在极性有机溶剂中表现出异常高的溶解度。电导率测量表明配合物(2a和2b)在CH3CN溶液中离子解离。 X射线分析结果证实2a中心点3H2O中心点THF是阳离子有机金属路易斯酸。由于 10-甲基吖啶酮和 2a 之间形成强烈的络合物，UV/Vis 光谱显示出显着的红移。荧光光谱显示2a的路易斯酸度介于Sc3+ (lambda em=474 nm)和Fe3+ (lambda em=478 nm)之间。 ESR光谱显示2a的路易斯酸度（0.91 eV）与Sc3+（1.00 eV）和Y3+（0.85 eV）处于同一水平，而2b的路易斯酸度（1.06 eV）大于Sc3+（1.00 eV）和Y3+（0.85 eV）。它们在羰基化合物转化反应中表现出很高的催化能力，例如曼尼希反应、向山羟醛反应、醛的烯丙基化、烷基芳族醚的FriedelCrafts酰化和酮的环三聚反应。此外，该配合物具有良好的可重复使用性。由于其优异的催化效率、稳定性和可重复使用性，该配合物将在有机合成中找到广泛的催化应用。
Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s [M(Cp)2][OSO2C8F17]2 center dot nH2O center dot THF (M=Zr (2a center dot 3H2O center dot THF), M=Ti (2b center dot 2H2O center dot THF)) were synthesized by the reaction of [M(Cp)2]Cl2 (M=Zr (1a), M=Ti (1b)) with nBuLi and C8F17SO3H (2 equiv) or with C8F17SO3Ag (2 equiv). The hydrate numbers (n) of these complexes were variable, changing from 0 to 4 depending on conditions. In contrast to well-known metallocene triflates, these complexes suffered no change in open air for a year. thermogravimetrydifferential scanning calorimetry (TG-DSC) analysis showed that 2a and 2b were thermally stable at 300 and 180 degrees C, respectively. These complexes exhibited unusually high solubility in polar organic solvents. Conductivity measurement showed that the complexes (2a and 2b) were ionic dissociation in CH3CN solution. X-ray analysis result confirmed 2a center dot 3H2O center dot THF was a cationic organometallic Lewis acid. UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2a. Fluorescence spectra showed that the Lewis acidity of 2a fell between those of Sc3+ (lambda em=474 nm) and Fe3+ (lambda em=478 nm). ESR spectra showed the Lewis acidity of 2a (0.91 eV) was at the same level as that of Sc3+ (1.00 eV) and Y3+ (0.85 eV), while the Lewis acidity of 2b (1.06 eV) was larger than that of Sc3+ (1.00 eV) and Y3+ (0.85 eV). They showed high catalytic ability in carbonyl-compound transformation reactions, such as the Mannich reaction, the Mukaiyama aldol reaction, allylation of aldehydes, the FriedelCrafts acylation of alkyl aromatic ethers, and cyclotrimerization of ketones. Moreover, the complexes possessed good reusability. On account of their excellent catalytic efficiency, stability, and reusability, the complexes will find broad catalytic applications in organic synthesis.