Enantioselective hydrolysis of (RS)-2-fluoroarylacetonitriles using nitrilase from Arabidopsis thaliana

The enzymatic resolution of 2-fluoroarylacetonitriles (RS)-3 using nitrilas e from the plant Arabidopsis thaliana is described. Racemic 2-fluoronitrile s 3 are easily accessible from O-silylated aromatic cyanohydrins 2 by react ion with DAST. The nitriles (RS)-3 were hydrolysed with the nitrilase as a catalyst, not to the expected 2-fluoroarylacetic acids but to the correspon ding (R)-2-fluoroarylacetamides (R)-5 as the main products. After optimizat ion of reaction conditions (pH 9, 7 degreesC), the enantiomeric excesses of (R)-5a,c and f (R=H, 3-Me, 3-OMe) could be improved to >99% by one recryst allization. The acid catalysed hydrolysis of (R)-5a,5c and 5f afforded the corresponding (R)-2-fluoroarylacetic acids (R)-4a,Je and 4f without racemiz ation. (C) 2001 Elsevier Science Ltd. All rights reserved.