有机无机杂化硅材料负载手型铑催化剂制备及催化活性研究

发布时间：2018-04-13 15:05

本文选题：不对称氢转移 + 1　；参考：《上海师范大学》2016年硕士论文

【摘要】：咪唑摀盐型有机-无机杂化硅材料的优势在于制备简单,易于修饰。作为一种具有双功能特性的复合型载体,它本身在催化反应中具有相转移催化的作用,在参与多相催化反应中具有更加良好的效果。此外,该材料还具有较高的热力学稳定性,同时表面具有大量的羟基,便于催化剂的修饰与固载。而且羟基大多分布于材料的表面,基于这些特性制备出的固载型催化剂的活性位点分布更加广泛和均匀,这种材料具有开放的层状微观结构,有利于底物接近催化活性中心,同时也有利于提高产物立体选择性。有序介孔有机硅材料(PMO)具有的较大的比表面积和孔容,可控的孔径及排列有序的孔分布,较高的热力学和机械稳定性,PMO材料有其特定的性质如具有很高的疏水性,他们内在的有机硅的内表面上显著的促进有机官能团的变换。基于这两种材料各方面的优点,本文设计合成了两类负载型催化剂并对其各自的催化性能进行了探究。(1)合成了一种参杂了咪唑摀盐有机-无机杂化硅材料作为载体固载了手性前驱体(Cp*RhTs-DPEN-PMO)得到一种非均相相催化剂,它们展示出了与均相催化剂相当的催化活性和对映体选择性。系统地研究了该催化剂在水相中用于催化芳香酮及其他类似酮不对称氢转移反应,在催化活性和立体选择性上都有与均相催化剂相当甚至更好的表现,更重要的是非均相催化剂在对α-卤代苯乙酮和苯偶先类化合物进行不对称氢转移时可以通过离心很方便的回收再利用,循环使用8次仍保持很好的催化活性和立体选择性。表现出其在催化合成中的广阔前景和潜在的应用价值。(2)合成了一种有序介孔有机硅材料PMO(1)作为载体固载了手性前驱体S/Olefin-Rh催化剂得到非均相催化剂S/Olefin-PMO(2),再络合金属铑催化剂得到S/Olefin-Rh-PMO(3)展示出了与均相催化剂相当的催化活性和对映体选择性。并且通过表征,证明了均相催化剂S/Olefin-Rh已经成功地固载到有序介孔有机硅材料PMO(1)上。更重要的是,更重要的是非均相催化剂S/Olefin-PMO(2)络合金属催化剂铑在对1,2-加成反应时可以通过离心很方便的回收再利用,重复实用8次以上,还能表现出优异的活性和对映体选择性,表现出其在催化合成中的广阔前景和潜在的应用价值。
[Abstract]:The advantages of imidazolium organic-inorganic hybrid silicon are simple preparation and easy modification.As a compound carrier with bifunctional characteristics, it has the function of phase transfer catalysis in catalytic reaction, and it has better effect in participating in multiphase catalytic reaction.In addition, the material also has high thermodynamic stability and a large number of hydroxyl groups on the surface, which is convenient for the modification and immobilization of the catalyst.Moreover, the hydroxyl groups are mostly distributed on the surface of the materials. The active sites of the supported catalysts based on these properties are more widely and uniformly distributed. This kind of material has an open layered microstructure, which is favorable for the substrate to approach the catalytic active center.It also helps to improve the stereoselectivity of the product.The inner surface of their intrinsic organosilicon significantly promotes the transformation of organic functional groups.Based on the advantages of these two materials,Heterogeneous catalyst,They exhibit the same catalytic activity and enantioselectivity as homogeneous catalysts.The catalytic activity and stereoselectivity of the catalyst for asymmetric hydrogen transfer reaction of aromatic ketones and other ketones in aqueous phase were studied systematically, and the catalytic activity and stereoselectivity of the catalysts were comparable to or better than those of homogeneous catalysts.What is more important is that the heterogeneous catalyst can be easily recovered and reused by centrifugation in the asymmetric hydrogen transfer of 伪 -haloacetophenone and benzene-diploid compounds, and the catalytic activity and stereoselectivity can be maintained for 8 cycles.A kind of ordered mesoporous organosilicon (PMO1) was synthesized as the support of chiral precursor S/Olefin-Rh catalyst to obtain heterogeneous catalyst S / Olefin-PMO-2N and complex metal rhodium.The catalytic activity and enantioselectivity of S- / Olefin-Rh-PMO-3 are comparable to those of homogeneous catalyst.It is proved that the homogeneous catalyst S/Olefin-Rh has been successfully immobilized on the ordered mesoporous organosilicon (PMO1).More importantly, the heterogeneous catalyst S / Olefin-PMO-2) complex metal catalyst rhodium can be easily recovered and reused by centrifugation, reused for more than eight times, and can also exhibit excellent activity and enantioselectivity.It shows broad prospect and potential application value in catalytic synthesis.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36

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