Geminal Brønsted acid ionic liquids as catalysts for the Mannich reaction in water.
Quaternary ammonium geminal Brønsted acid ionic liquids (GBAILs) based on zwitterionic 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane (where the carbon number of the alkyl chain is 4, 8, 10, 12, 14, 16, or 18) and p-toluenesulfonic acid monohydrate were synthesized. The catalytic ionic liquids were applied in three-component Mannich reactions with an aldehyde, ketone, and amine at 25 °C in water. The effects of the type and amount of catalyst and reaction time as well as the scope of the reaction were investigated. Results showed that GBAIL-C14 has excellent catalytic activity and fair reusability. The catalytic procedure was simple, and the catalyst could be recycled seven times via a simple separation process without noticeable decreases in catalytic activity.
School of Chemical Engineering, Hebei University of Technology, Tianjin 300130, China. heleqin@163.com.
Leqin
L
He
Key Laboratory for Resource Exploration Research of Hebei Province, Hebei University of Engineering, Handan 056038, China. qinsj528@hebeu.edu.cn.
Shenjun
S
Qin
Key Laboratory for Resource Exploration Research of Hebei Province, Hebei University of Engineering, Handan 056038, China. changt03@sina.com.
Tao
T
Chang
Key Laboratory for Resource Exploration Research of Hebei Province, Hebei University of Engineering, Handan 056038, China. sun_yz@hotmail.com.
Yuzhuang
Y
Sun
School of Chemical Engineering, Hebei University of Technology, Tianjin 300130, China. zhaojq@hebut.edu.cn.
Jiquan
J
Zhao
D000143:Acids / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001557:Benzenesulfonates / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D052578:Ionic Liquids / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D008352:Mannich Bases / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D000143:Acids; D000447:Aldehydes; D000588:Amines; D001557:Benzenesulfonates; D052578:Ionic Liquids; D007659:Ketones; D008352:Mannich Bases; D000644:Quaternary Ammonium Compounds; D014867:Water; C029501:4-toluenesulfonic acid