Synthesis of Helical Poly(phenylacetylene)s with Amide Linkage Bearing l-Phenylalanine and l-Phenylglycine Ethyl Ester Pendants and Their Applications as Chiral Stationary Phases for HPLC

Novel stereoregular helical poly(phenylacetylene) derivatives ( PPA-Phe and PPA-Phg ) with an amide linkage bearing l -phenylalanine and l -phenylglycine ethyl ester pendants were synthesized for use as chiral stationary phases (CSPs) in HPLC. The polymers showed different chiral recognition abilities depending on the coating solvents. Both PPA-Phe and PPA-Phg exhibited higher chiral recognitions when coated with CHCl 3 by having preferable conformations. Their chiral recognition abilities depended on their molecular weight and optical rotations which were influenced by the polymerization solvents and monomer concentration. PPA-Phe and PPA-Phg showed rather different chiral recognitions, indicating that the benzyl group of the former and the phenyl group of the latter also play important roles in the chiral recognition. A few racemates were completely separated on PPA-Phe or PPA-Phg with separation factors comparable or higher than those obtained on the popular polysaccharide-based CSPs.