Synthesis and chiral recognition of helical poly(phenylacetylene)s bearing l-phenylglycinol and its phenylcarbamates as pendants.

ABSTRACT A series of novel stereoregular one-handed helical poly(phenylacetylene) derivatives ( PPA-1 and PPA-1a∼g) bearing l-phenylglycinol and its phenylcarbamate residues as pendants was synthesized for use as chiral stationary phases (CSPs) for HPLC, and their chiral recognition abilities were evaluated using 13 racemates. The phenylcarbamate residues include an unsubstituted phenyl, three chloro-substituted phenyls (3-Cl, 4-Cl, 3,5-Cl2), and three methyl-substituted phenyls (3-CH3, 4-CH3, 3,5-(CH3)2). The acidity of the phenylcarbamate N-H proton and the hydrogen bonds formed between the N-H groups of the phenylcarbamate residues were dependent on the type, position, and the number of substituents on the phenylcarbamate residues. The chiral recognition abilities of these polymers significantly depended on the dynamic helical conformation of the main chain with more or less regularly arranged pendants. The chiral recognition abilities seem to be improved by the introduction of substituents on the phenylcarbamate residues, and PPA-1d bearing the more acidic N-H groups due to the 3,5-dichloro substituents, exhibited a higher chiral recognition than the others. PPA-1d showed an efficient chiral recognition for some racemates, and baseline separation was possible for racemates 5, 11, 12, and 15. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 809-821 [ABSTRACT FROM AUTHOR]