Novel DBU-based hydroxyl ionic liquid for efficient Knoevenagel reaction in water
| Autor: | Sanhu Zhao, Dan Meng, Lingling Wei, Yongsheng Qiao, Fugui Xi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Green Chemistry Letters and Reviews, Vol 12, Iss 3, Pp 271-277 (2019) |
| Druh dokumentu: | article |
| ISSN: | 1751-8253 1751-7192 17518253 |
| DOI: | 10.1080/17518253.2019.1637946 |
| Popis: | Novel ionic liquid N-(2-hydroxy-ethyl)-DBU bromide ([HyEtDBU]Br), based on 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) and 2-bromoethanol, was introduced as catalyst for Knoevenagel condensation. Comparing with other non-hydroxyl ionic liquids, [HyEtDBU]Br showed a better catalytic activity, the hydroxyl group linked on the ionic liquid played an important role in facilitating the Knoevenagel condensation reaction. In the presence of [HyEtDBU]Br-H2O-DABCO composite system, the corresponding Knoevenagel adducts were obtained in good to excellent yields within short times in all cases examined, the procedure is simple and the desired products could be easily separated and purified without any requirement of column chromatographic purification. The use of water as the reaction medium makes the process environmentally benign. The composite system [HyEtDBU]Br-H2O can be recycled eight times without activity loss. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|