Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (5): 997-1003.DOI: 10.1016/S1872-2067(18)63023-2

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Chiral basket-handle porphyrin-Co complexes for the catalyzed asymmetric cycloaddition of CO2 to epoxides

Xiying Fua, Xinyao Jinga, Lili Jinb, Lilong Zhanga, Xiaofeng Zhanga, Bin Huc, Huanwang Jinga,d   

  1. a State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, China;
    b College of Sciences, China Pharmaceutical University, Nanjing 210009, Jiangsu, China;
    c State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China;
    d State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
  • Received:2017-12-06 Revised:2017-12-27 Online:2018-05-18 Published:2018-04-19
  • Contact: 10.1016/S1872-2067(18)63023-2
  • Supported by:

    This work was financially supported by the National Natural Science Foundation of China (21173106, 20973086), the Natural Science Foundation of Gansu Province (17JR5RA212), and the Foundation of State Key Laboratory of Coal Conversion (J17-18-913-2).

Abstract:

The catalytic synthesis of cyclic carbonates via the cycloaddition of CO2 to epoxides is a standard methodology for CO2 fixation. For this purpose, chiral basket-handle porphyrin-Co complexes were devised, prepared, and fully characterized by nuclear magnetic resonance, mass spectrometry, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and specific rotation. The proposed metalloporphyrin catalysts were synthesized with either 1,1'-bi-2-naphthol or L-phenylalanine, which have different chirality, and then applied to the coupling of propylene oxide and CO2 for generating chiral cyclic carbonates with good enantioselectivity under extremely mild conditions in the presence of tetrabutyl ammonium chloride as a co-catalyst. The good enantioselectivity in the cycloaddition reaction is attributed to a synergistic interplay between the chiral porphyrin catalysts and the substrate. The mechanism and enantioselectivity of the asymmetric cycloaddition reaction is discussed.

Key words: Carbon dioxide fixation, Chiral resolution, Cycloaddition, Epoxide, Chiral porphyrin-cobalt complex