Nmp-based ionic liquids: Recyclable catalysts for both hetero-Michael addition and Knoevenagel condensation in water

ABSTRACT

A series of novel N-methyl piperidine (Nmp)-based ionic liquids with 1,2-propanediol group are synthesized and used as catalysts for both hetero-Michael addition of α,β-unsaturated amides and Knoevenagel condensation at room temperature in water; and all the examined substrates could be transformed into corresponding products in good to excellent yields. Meanwhile IL-catalyzed hetero-Michael addition of α,β-unsaturated amides in water has not been reported in the previous literatures. Additionally, the catalyst is recyclable for the two reactions. This finding provides a green catalyst for both hetero-Michael addition of α,β-unsaturated amides and Knoevenagel condensation in water.

GRAPHICAL ABSTRACT

KEYWORDS:

• α,β-Unsaturated amide
• hetero-Michael addition
• in water
• ionic liquid catalyzed
• Knoevenagel condensation

Additional information

Funding

This work was supported by National Natural Science Foundation of China (Grant Nos. 21502042, 51403051, 21477033), Scientific Research Key Project Fund of Henan Provincial Education Department (Grant Nos. 15A150041, 16A150003), Scientific Research Fund of Henan University (No. 2013YBZR008).