Experimental and computational study on the factors affecting the structure of L-proline-catalyzed Knoevenagel condensation

The Knoevenagel condensation of aromatic aldehydes and ethyl acetoacetate catalyzed by L-proline in water, ionic liquid, and deep eutectic solvents (DESs), respectively, was studied. The mild reaction conditions, enhanced rates, improved yields, and reagents’ reactivity are observed in deep eutectic solvents. The highest yields are up to 94.4%. The Z/E selectivity of products is up to 3.21. In addition, the influencing factors of product configuration were studied by calculation and experiment.