5-Hydroxypentylammonium acetate as a reusable ionic liquid catalyzes tandem Knoevenagel-phospha-Michael reaction of aldehydes, malononitrile and phosphites

5-Hydroxypentylammonium acetate as a task-specific ionic liquid promotes efficient tandem Knoevenagel-phospha-Michael reaction of phosphite esters with aryl/heteroaryl/alkyl/salicylaldehydes and malonitrile/ethyl cyanoacetate at room temperature in short reaction times. This simple procedure allows a series of ??-phosphonomalonates and 4-substituted 2-amino-4H-chromenes with phosphonic acid dialkyl esters to be synthesized in good to high yields in the presence of an ionic liquid for the first time.