Potassium sorbate as an efficient and green catalyst for Knoevenagel condensation.

Potassium sorbate has been utilized as a novel, efficient and green catalyst for the Knoevenagel condensation of aromatic aldehydes with active methylene compounds to afford substituted ole-fins through the conventional stirring or under ultrasound irradiation. Improvements were observed by carrying out the reactions under ultrasound irradiation. The advantages of this procedure are mild reaction conditions, high yields, cleaner reaction profiles and operational simplicity.