To a vial were added sequentially the catalyst cinchonidine thiourea (3b, 5.6 mg, 0.010 mmol, 10 mol%), isatin (6a, 14.7 mg, 0.10 mmol), malononitrile (7, 6.6 mg, 0.10 mmol), toluene (1.0 mL) and water (0.050 mL). The mixture was stirred at 0 °C for 10 min before the addition of isopropyl acetoacetate (8d, 14.4 mg, 0.10 mmol). The reaction mixture was further stirred at 0 °C for 15 h. Upon the completion (monitored by TLC), the reaction mixture was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The crude reaction mixture was purified by flash column chromatography with a 40:60 hexane/EtOAc mixture as the eluent to yield to product 9f (27.8 mg, 82%) as a white solid. The enantiomeric ratio was determined by HPLC analysis on a chiral ChiralPak IB column.