Enantioselective Synthesis of (R)-2-Arylpropanenitriles Catalysed by Ene-Reductases in Aqueous Media and in Biphasic Ionic Liquid-Water Systems

The enantioselective reduction of a-methylene nitrile derivatives catalysed by ene-reductases affords the corresponding (R)-2-arylpropanenitriles with high conversion values. The reaction is investigated either in aqueous medium (with an organic cosolvent or by loading the substrate onto hydrophobic resins) or in a biphasic ionic liquid-water system. The use of ionic liquids, herein with isolated ene-reductases, is found to improve the work-up and the substrate recovery method. The synthetic manipulation of the final chiral nitrile derivatives indicates how this biocatalysed method can be exploited for the preparation of a wide range of chiral compounds.