Efficient lipase-catalyzed Knoevenagel condensation: utilization of biocatalytic promiscuity for synthesis of benzylidene-indolin-2-ones.

Based on the screening of biocatalysts and reaction conditions including solvent, water content, temperature, enzyme loading, and reaction time, lipase from porcine pancreas (PPL) showed the prominent promiscuity for the Knoevenagel condensation between 1,3-dihydroindol-2-one heterocycle and aromatic aldehydes. Under the optimized procedure, both electron-withdrawing and electron-donating substituent of aldehydes substrates could react efficiently, and benzylidene-indolin-2-ones were obtained in excellent yields (75.0-96.6%). Benzylidene-indolin-2-ones derivatives were efficiently synthesized by the Knoevenagel condensation between various aromatic aldehydes and 1,3-dihydroindol-2-one catalyzed by lipase from porcine pancreas with excellent yields obtained.