Chinese Journal of Catalysis ›› 2012, Vol. 33 ›› Issue (5): 891-897.DOI: 10.3724/SP.J.1088.2012.11213

• Research papers • Previous Articles     Next Articles

Immobilization of Cinchona Quaternary Ammonium Salts as the Chiral Phase Transfer Catalysts on Multi-walled Carbon Nanotubes and Their Application in Enantioselective Alkylation

LIU Jian1, LIU Yan2,a, SHI Xin1,b, YANG Qihua2,c   

  1. 1Institute of Chemistry for Functionalized Materials, School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, Liaoning, China; 2State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2011-12-10 Revised:2012-03-02 Online:2012-05-09 Published:2012-05-09

Abstract: The pyrene-tagged cinchona quaternary ammonium salt, the chiral phase transfer catalysts (PTC-1), was synthesized and immobilized on multi-walled carbon nanotubes (MWCNTs). The new catalysts (PTC-1/MWCNTs) were employed in enantioselective alkylation of N-(diphenylmethyene)glycine tert-butyl ester. UV-Vis absorption spectra show the effect of different organic solvents on the adsorption and desorption of PTC-1 onto and from MWCNTs, respectively. The results show that 5.3 mg PTC-1 can be loaded on 10 mg MWCNTs in toluene, and 0.02025 mg PTC-1 was desorbed from 12.7 mg PTC-1/MWCNTs when washed by CHCl3. In the enantioselective alkylation of different halohydrocarbons with N-(diphenylmethyene)glycine tert-butyl ester using PTC-1/MWCNTs as a catalyst, the alkylating products were obtained with high yield and ee value. Furthermore, PTC-1/MWCNTs catalyst can be recovered and used repeatedly. PTC-1/MWCNTs as a new catalyst is effective in enantioselective alkylation of multiple halohydrocarbon.

Key words: multi-walled carbon nanotube, chiral phase transfer catalyst, cinchona alkaloid, adsorption, enantioselective alkylation