Asymmetric reduction of 3-chloropropiophenone to ( S)-3-chloro-1-phenylpropanol using immobilized Saccharomyces cerevisiae CGMCC 2266 cells

Abstract

( S)-3-Chloro-1-phenylpropanol is an important chiral precursor for numerous antidepressants such as tomoxetine. A high enantiomeric excess (e.e.) of ( S)-3-chloro-1-phenylpropanol can be achieved by asymmetric reduction of 3-chloropropiophenone using Saccharomyces cerevisiae CGMCC 2266 cells immobilized in calcium alginate. Thermal pretreatment of the immobilized cells at 50 °C for 30 min resulted in high enantioselectivity (99% e.e.) and good percent conversion (80%). The effects of various conditions on the reduction reaction were investigated. The optimal conditions were found to be as follows: sodium alginate concentration, 2%; bead diameter, 2 mm; temperature, 30 °C; re-culture time, 24 h; and batch addition of the substrate. After reusing these three times, the immobilized cells retained approximately 60% of their original catalytic activity with their enantioselectivity intact.