Sulfated polyborate as Bronsted acid catalyst for Knoevenagel condensation

We have developed the use of Bronsted acid for Knoevenagel condensation. Sulfated polyborate has been used for efficient Knoevenagel condensation of aromatic, heterocyclic, alpha,beta-unsaturated, and aliphatic aldehydes in the ecologically friendly ethanol: water (1:1) mixture as solvent at 70 degrees C. It took less time for certain aldehydes to react with active methylenes. The present method demonstrated significant benefits in terms of first-time use of Bronsted acid catalyst, mild reaction conditions, and better product yields.

Automated summary

We have developed a method using Bronsted acid for Knoevenagel condensation. This method efficiently reacts aromatic, heterocyclic, alpha,beta-unsaturated, and aliphatic aldehydes in an environmentally friendly solvent mixture of ethanol and water at 70 degrees C. The method shows significant benefits in terms of using a Bronsted acid catalyst for the first time, mild reaction conditions, and improved product yields.