Optically active aryl alcohols are a kind of important chiral building blocks for the synthesis of chiral drugs. In recent years, the preparations of enantiopure aryl alcohols have become one of the focus points in organic chemistry. Compared with conventional chemical processes, biocatalysis is more attractive due to its high enantioselectivity, mild and safe reaction conditions and less environmental hazards. Asymmetric bioreduction of aryl ketones is the most effective method for the synthesis of enantiopure aryl alcohols. This paper mainly reviews the recent progress in the preparation of chiral aryl alcohols by asymmetric bioreduction catalyzed by microbial whole-cells, enzymes, genetically engineered bacteria or yeasts, as well as immobilized cells. The effects of substrate co-solvents such as organic solvents, surfactants and ionic liquids on asymmetric bioreduction are further summarized. The prospect of the preparation of enantiopure aryl alcohols by asymmetric bioreduction is also discussed.
Contents
1 Introduction
2 Bioreduction of aryl ketones by microbial whole cells
2.1 Biocatalysis by eukaryotic microbes
2.2 Biocatalysis by prokaryotic microbes
3 Bioreduction of aryl ketones by plant cells
4 Bioreduction of aryl ketones by purified enzymes
5 Bioreduction of aryl ketones by recombinant whole cells
6 Bioreduction of aryl ketones by immobilized cells
7 Effects of substrate co-solvents on the bioreduction
7.1 Organic solvents as co-solvent
7.2 Surfactants as co-solvent
7.3 Ionic liquids as co-solvent
8 Conclusion