Basic polymerized imidazolide-based ionic liquid: an efficient catalyst for aqueous Knoevenagel condensation. Issue 27 (25th February 2015)

• Record Type: Journal Article
• Authors: Ding, Libing; Li, Hansheng; Zhang, Yaping; Zhang, Kun; Yuan, Hong; Wu, Qin; Zhao, Yun; Jiao, Qingze; Shi, Daxin
• Is Part Of: RSC advances. Volume 5:Issue 27(2015)
• Page Start: 21415
• Page End: 21421
• Publication Date: 2015-02-25
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra01700a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A novel basic polymerized ionic liquid (BPIL) with intensive base sites and high surface activity was synthesized and characterized by IR, 1 H NMR and ESI-MS. The BPIL was used as an efficient catalyst for aqueous Knoevenagel condensations. Abstract : A novel basic polymerized ionic liquid (BPIL): polymeric 1-[(4-ethenylphenyl)methyl]-3-propylimidazolium imidazolide was synthesized and characterized by Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and electron spray ionization mass spectrometry (ESI-MS). The BPIL was used as an efficient catalyst for aqueous Knoevenagel condensations with extended substrates. In comparison with common base catalysts, the BPIL showed high catalytic activity, which was ascribed to the cooperation between the strong basicity and the high surface activity. Moreover, the BPIL with high molecular weight has high surface activity and low catalytic activity. In addition, the BPIL was easily recovered and maintained high catalytic activity after five cycles of use in the system using benzaldehyde and malononitrile as substrates.