Optical resolution of racemic amino acid derivatives with chiral polyamides bearing glutamyl residue as a diacid component

Novel chiral polyamides with chiral environment in their main chains were obtained from aromatic diamine, 4,4′‐diaminodiphenylmethane (DADPM), and the D ‐isomer or the L ‐isomer of N‐α‐protected glutamic acid, such as N‐α‐benzyloxycarbonyl‐D ‐glutamic acid (Z‐D ‐Glu‐OH) or N‐α‐benzyloxycarbonyl‐L ‐glutamic acid (Z‐L ‐Glu‐OH), in the presence of triphenyl phosphite (TPP). Two types of newly prepared polyamide showed optical rotation, implying that there were asymmetric carbons in their main chains. Circular dichroism studies demonstrated that resulting chiral poly‐ amides took a helical structure. Optical resolution ability of those two types of polyamide was studied by adopting potential difference as a driving force for membrane transport. Membranes showed permselectivity toward racemic mixture of N‐α‐acetyltryptophan (Ac‐Trp). The permselectivity was dependent on the absolute configuration of diacid component. The permselectivity was expressed by diffusivity selectivity, which was determined by the presence of chiral helicity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011