ENANTIOSELECTIVE SYNTHESIS OF AMINO-ACID AMIDES VIA ENZYMATIC AMMONIOLYSIS OF AMINO-ACID ESTERS

Ammoniolysis of D,L-phenylglycine methyl ester catalysed by Candida an tarctica B lipase (Novozym 435) gave D-phenylglycine amide with 78% ee at 47% conversion. The combination of this reaction with racemisation of the unconverted ester in a single step was investigated. Pyridoxal and salicylaldehyde efficiently catalysed the racemisation of the est er. Because the solubility of the amide was law under the reactions co nditions, its racemisation was slow. Ln-process racemisation of the re actant gave D-phenylglycine amide with 73% ee at 85% conversion. (C) 1 998 Elsevier Science B.V. All rights reserved.