Novel Task-Specific Ionic Liquids as Solvents for Michael Addition of Methylene Active Compounds to Chalcones Without Any Catalyst

Abstract

A convenient and facile method for Michael addition of methylene active compounds to chalcones has been developed by using 1,8-diazabicyclo [5.4.0]undec-7-ene- derived task-specific ionic liquids as reaction medium in the absence of any catalyst. This protocol could afford the Michael adducts in good to excellent yields in a short time, the workup is very simple, and the ionic liquid could be reused six times without significant loss of activity.

GRAPHICAL ABSTRACT

Keywords:

• Methylene active compounds
• Michael addition
• recyclability
• task-specific ionic liquid

ACKNOWLEDGMENTS

We are grateful to the National Natural Sciences Foundation of China (No. 21106090) and Postdoctoral Foundation of China (No. 2012M511352) for financial support.

Notes

^a Reaction conditions: chalcone (1 mmol) and malononitrile (1 mmol) at rt.

^b Isolated yields.

^a Reaction conditions: methylene compounds (1.0 mmol), chalcones (1.0 mmol), and 2 mL [DBU][Lac] at rt.

^b Isolated yield.

^c Result from Ref. 13.

^d Result from Ref. 14.

^a Reaction conditions: chalcone (1 mmol), acetyl acetone (1 mmol), and [DBU][Lac] (2 mL) without any catalyst at rt.

^b Isolated yield.