Kinetic study on enantioselective resolution of (R,S)-2-phenylpropionic acid through Novozyme 435–catalyzed esterification

2-Phenylpropionic acid (2-PPA) is a very important chiral intermediate in the synthesis of aryl propionic acid drugs with anti-inflammatory and analgesic effects. Enzymatic kinetic resolution of (R,S)-2-PPA using n-hexanol as an acyl donor was carried out in n-hexane. Lipases from different sources were used to catalyze the esterification of 2-PPA, among which Novozyme 435 had the highest catalytic efficiency. The effects of reaction conditions on conversion (c) and enantiomeric excess (ee), involving temperature, substrate concentrations, enzyme loading, and reaction time were investigated. The kinetic model based on the Ping-Pong bi-bi mechanism was established to simulate the enzymatic esterification process. The experimental values of initial rates of various 2-PPA concentrations were consistent with the simulated values.