A new efficient enantioselective synthesis of malonylphenylalanyl and malonylmethylphenylalanyl derivatives suitable for solid phase peptide synthesis

A new synthesis of enantiomerically pure malonylphenylalanyl and malonylmethylphenylalanyl derivatives was developed in which the corresponding prochiral enamides were treated by asymmetric hydrogenation using the Rh(I)-(S,S)-Me-DuPHOS system. These unnatural amino acids were suitably protected and can be used in solid phase peptide synthesis.

We describe the enantioselective synthesis of two para-malonylphenylalanyl and para-malonylmethylphenylalanyl derivatives suitably protected by Fmoc, Boc or Cbz. These compounds can be incorporated into peptides by solid phase synthesis.