Imidazolium Polyoxometalate: An Ionic Liquid Catalyst for Esterification and Oxidative Esterification

Authors

  • Huan Li,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Yunxiang Qiao,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Li Hua,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Prof. Dr. Zhenshan Hou,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Bo Feng,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Zhenyan Pan,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Yu Hu,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Xiangrui Wang,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Xiuge Zhao,

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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  • Yinyin Yu

    1. Key Laboratory for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237 (China), Fax: (+86) 21-6425-3372
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Abstract

A new family of polyoxometalate-based ionic liquids (POM-IL) is synthesized, characterized, and employed as catalysts in the esterification of various alcohols with acetic acid. The ionic liquid catalyst shows high activity and gives excellent yields of esters. An emulsion forms between the IL catalyst and substrates during the reaction and promotes the catalytic process. After reaction, the emulsion can conveniently be broken by the addition of a weakly polar organic solvent to facilitate the separation of the catalyst. On the basis of the above results, a direct transformation of benzaldehyde to methyl ester under relatively mild conditions is also developed in the absence of any cocatalyst. Finally, the scope of the substrates and recyclability of the catalyst are also investigated.

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