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Readily accessible mesoporous silica nanoparticles supported chiral urea‐amine bifunctional catalysts for enantioselective reactions
Applied Organometallic Chemistry ( IF 3.7 ) Pub Date : 2020-10-05 , DOI: 10.1002/aoc.6015
Yaşar Gök 1 , İrem Tutkum Aykut 1 , Halil Zeki Gök 1
Affiliation  

The main objective of this study is to develop readily accessible and recyclable solid catalysts for enantioselective reactions. To achieve this, magnetic MCM‐41 and non‐magnetic SBA‐15 mesoporous supports were prepared, then mesoporous silica supported chiral urea‐amine bifunctional catalysts were synthesized by grafting of chiral urea‐amine ligand onto SBA‐15 and magnetic MCM‐41. The magnetic and non‐magnetic supports and so‐prepared solid catalysts were characterized by using different methods such as N2 sorption measurements, Fourier transform infrared spectroscopy (FT‐IR), field emission scanning electron microscope‐energy dispersive X‐ray analysis (FESEM‐EDX), X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). Results showed that (1R, 2R) or (1S, 2S)‐1,2‐diphenylethane‐1,2‐diamine was successively immobilized onto magnetic MCM‐41 and SBA‐15 pores. The heterogeneous chiral solid catalysts and their homogenous counterparts exhibited high activities both enantioselective transfer hydrogenation reaction (up to 99% conversion and 65% ee) and enantioselective Michael reaction (up to 98% conversion and 26% ee). Moreover, the SBA‐15 supported solid catalysts were separated from the reaction mixture by simple filtration, whereas the magnetic MCM‐41 supported solid catalysts were separated by simple magnetic decantation and reused in three consecutive catalytic experiments.

中文翻译:

易于获得的介孔二氧化硅纳米颗粒支持手性脲胺双功能催化剂,用于对映选择性反应

这项研究的主要目的是开发对映选择性反应容易获得和可回收的固体催化剂。为此,制备了磁性MCM-41和非磁性SBA-15介孔载体,然后通过将手性脲-胺配体接枝到SBA-15和磁性MCM-41上,合成了介孔二氧化硅负载的手性脲-胺双功能催化剂。磁性和非磁性载体以及如此制备的固体催化剂的特征在于使用了不同的方法,例如N 2吸附测量,傅里叶变换红外光谱(FT-IR),场发射扫描电子显微镜-能量色散X射线分析(FESEM) -EDX),X射线衍射(XRD)和热重分析(TGA)。结果表明(1 R,2 R)或(1 S,2 S)-1,2-二苯乙烷-1,2-二胺先后固定在磁性MCM-41和SBA-15孔中。非均相手性固体催化剂及其均相对应物均表现出高活性,既对映选择性转移氢化反应(转化率高达99%和ee 65%)和对映选择性迈克尔反应(转化率高达98%和ee 26%)。此外,通过简单过滤将SBA-15负载的固体催化剂从反应混合物中分离出来,而通过简单的磁倾析将磁性的MCM-41负载的固体催化剂分离出来并在三个连续的催化实验中重复使用。
更新日期:2020-11-06
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