Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (07): 1572-1581.doi: 10.3866/PKU.WHXB201304243

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Asymmetric Hydrogenation of Aromatic Ketones Catalyzed by Cinchona-Modified Ir/SiO2

JIANG He-Yan1, WU Zhi-Feng1, CHEN Hua2   

  1. 1 Key Laboratory of Catalysis Science and Technology of Chongqing Education Commission, College of Environmental and Biological Engineering, Research Center of Pharmaceutical Chemistry and Chemical Biology, Chongqing Technology and Business University, Chongqing 400067;
    2 Key Laboratory of Green Chemistry and Technology, Ministry of Education, The Institute of Homogeneous Catalysis, College of Chemistry, Sichuan University, Chengdu 610064
  • Received:2013-02-04 Revised:2013-04-22 Published:2013-06-14
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21201184), Natural Science Foundation Project of Chongqing, China (CSTC, 2011BA5025), Research Fund of Chongqing Technology and Business University, China (2010-56-14), 100 Leading Scientists Promotion Project of Chongqing and Chongqing Innovative Research Team Development Program in University, China (KJTD201020).

Abstract:

The asymmetric hydrogenation of aromatic ketones catalyzed by cinchona- and triphenylphosphine (tpp)-modified Ir/SiO2 was studied. The heterogeneous enantioselective hydrogenation of heterocyclic ketones using a supported iridium catalyst was also investigated. Different analytical techniques, including inductively coupled plasma-atomic emission spectroscopy (ICP-AES), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), the Brunauer- Emmett-Teller (BET) method, infrared (IR) spectroscopy, 31P solid state nuclear magnetic resonance (NMR) spectroscopy, homogeneous- heterogeneous comparison experiment, conventional filtering test, and mercury poisoning experiment, were used to characterize the catalytic system. HRTEM, XPS, and the BET method clearly characterized the catalytic system. IR and 31P solid state NMR spectra provided useful information about the interactions between modifier, metal, and stabilizer. The homogeneous-heterogeneous comparison experiment, conventional filtering test, and mercury poisoning experiment clearly showed the differences between supported, and homogeneous catalysts. In addition, the effects of different stabilizers, modifiers, iridium content, solvents, and base additives on the asymmetric hydrogenation of aromatic ketones were investigated in detail. The results showed that cinchona alkaloids positively modified the Ir/ SiO2 catalyst. Under the optimum conditions, the hydrogenation enantioselectivities of acetophenone and its derivatives were 52%-96%. The enantioselectivities of the hydrogenation products of 4-acetopyridine, 2-acetothiophene, and 2-acetofuran reached 74%, 75%, and 63%, respectively.

Key words: Iridium, Cinchona alkaloid, Aromatic ketone, Asymmetric hydrogenation, Supported catalyst

MSC2000: 

  • O643