Chinese Journal of Catalysis ›› 2016, Vol. 37 ›› Issue (6): 979-986.DOI: 10.1016/S1872-2067(15)61084-1

• Articles • Previous Articles    

Lewis base-assisted Lewis acid-catalyzed selective alkene formation via alcohol dehydration and synthesis of 2-cinnamyl-1,3-dicarbonyl compounds from 2-aryl-3,4-dihydropyrans

Changhui Liua, Bin Pana, Yanlong Gua,b   

  1. a Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China;
    b State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
  • Received:2016-02-05 Revised:2016-03-15 Online:2016-05-30 Published:2016-05-30
  • Contact: Yanlong Gu
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21173089 and 21373093), the Fundamental Research Funds for the Central Universities of China (2014ZZGH019), and the Cooperative Innovation Center of Hubei Province.

Abstract:

Acid-catalyzed dehydration of alcohols has been widely employed for the synthesis of alkenes. However, activated alcohols when employed as substrates in dehydration reactions are often plagued by the lack of alkene selectivity. In this work, the reaction system can be significantly improved through enhancing the performance of Lewis acid catalysts in the dehydration of activated alcohols by combining with a Lewis base. Observations of the reaction mechanism revealed that the Lewis base component might have changed the reaction rate order. Although both the principal and side reaction rates decreased, the effect was markedly more observed on the latter reaction. Therefore, the selectivity of the dehydration reaction was improved. On the basis of this observation, a new route to synthesize 2-cinnamyl-1,3-dicarbonyl compounds was developed by using 2-aryl-3,4- dihydropyran as a starting substrate in the presence of a Lewis acid/Lewis base combined catalyst system.

Key words: Synergistic catalysis, Acid-base catalysis, Dehydration of alcohol, 2-Cinnamyl-1,3-dicarbonyl compound, Homogeneous catalysis