Chromatographic Optical Resolution by Optically Active Poly(diphenyl-2-pyridylmethyl methacrylate) with a Highly One-Handed Helical Structure

Abstract

ABSTRACT:The ability of optical resolution of ( -)-poly(diphenyl-2-pyridylmethyl methacrylate) (PD2PyMA) with highly one-handed helicity was investigated by using it as a chiral stationary phase for high-performance liquid chromatography. The optically active polymer was prepared with an organolithium complex of ( + )-(2S,3S)-dimethoxy-1,4-bis(l-perhydroazepinyl)-butane. When methanol was used as an eluent, PD2PyMA resolved many racemic compounds completely and several binaphthyl derivatives were better resolved than in resolution by optically active poly(triphenylmethyl methacrylate) (PTrMA). When a non-polar eluent, hexane-2-propanol mixture was used, PD2PyMA exhibited higher optical resolving power to several alcohols than PTrMA. This was ascribed to the strong interaction between the 2-pyridy) group of the PD2PyMA and the hydroxy group of the racemate in the non-polar eluent. In order to evaluate the durability of the column in methanol, the solvolysis rates of the monomer and chiral stationary phase were measured. This revealed that PD2PyMA has higher durability in methanol than PTrMA.

Asymmetric Anionic Polymerization of 1-Phenyldibenzosuberyl and 1-(2-Pyridyl)dibenzosuberyl Methacrylates and Chiral Recognition Ability of the Obtained Polymers

“…The half-life period for PDBSMA was ca. six times longer than that for TrMA 8 and that for 2PyDBSMA was 1.6 times longer than that for D2PyMA, 18 proving the validity of our monomer design. These results demon- strate the ester linkage in the polymers of PDBSMA and 2PyDBSMA to be more resistant against methanolysis than that in poly(TrMA) and poly(D2PyMA), respectively.…”

“…The resolution ability of poly(2PyDBSMA) appeared less than that of poly(D2PyMA). 18 This may be because the ester group of the poly(2PyDBSMA) cannot take a propeller structure, which is considered important in chiral recognition by poly(D2PyMA) and poly(TrMA), since the two phenyl groups are tied to each other. Alternatively, the ethylene group may prevent the effective enantioselective adsorption.…”

Chiral separation by chromatographic and electromigration techniques. A Review

“…More than 200 compounds were resolved on this CSP, which has been commercialized by Daicel. Polydiphenyl-2-pyridyl methacrylate (D2PyMA) was a further CSP developed by Okamoto's group [167]. Recently, Buchmeiser's group prepared polymers by ring-opening metathesis polymerization using norbornene derivatives of l-valine, l-phenylalanine [168] or b-CD [169] as monomers.…”

Chiral separations in capillary high-performance liquid chromatography and nonaqueous capillary electrochromatography using helically chiral poly(diphenyl-2-pyridylmethyl methacrylate) as chiral stationary phase

“…The first application of these polymers as chiral stationary phases (CSP) for enantioseparations in HPLC was described by Okamoto and co-workers [21,22]. PDPM as chiral selector is able to resolve enantiomers in methanol/ water as well as in less polar mobile phases such as nhexane/2-propanol.…”