Polymer-supported quininium, cinchoninium and cinchonidinium salts were used as phase transfer catalysts for the asymmetric C-alkylation of N-diphenylmethyleneglycine t-butyl ester in the synthesis of chiral phenylalanine, alanine, valine and 2-aminopent-4-enoic acid. The influence of the alkylation conditions on the chemical yields and the enantiomeric excesses were studied. The highest enantiomeric excess obtained was 27%. Although the enantiomeric excesses obtained in the present work are lower than those obtained in the corresponding non-supported reactions, they are nevertheless significantly higher than those obtained in most other polymer-supported phase transfer catalysed asymmetric syntheses so far reported in the literature.