Polymer‐bound cellulose phenylcarbamate derivatives as chiral stationary phases for enantioselective HPLC

Abstract

Novel chiral stationary phases (CSP) have been prepared by coating the internal surface of monodisperse macroporous poly(2-aminoethyl methacrylate-co-ethylene dimethacrylate) beads with dimethylphenylcarbamate derivatives of regenerated cellulose. The coating was achieved either by simple adsorption or by chemical bonding using a diisocyanate linker. Separation of enantiomers in normal-phase HPLC mode was used to evaluate the enantioselectivity of all CSPs. The influence of the properties of the polymer support such as pore size, pore volume, and content of the amine functionalities, reaction and separation conditions such as weight ratio of modified cellulose selector to polymer beads, amount of diisocyanate crosslinker, and the composition of the mobile phase on chiral discrimination and chromatographic resolution were also systematically investigated. The CSPs prepared by chemical anchoring were more stable and a wider range of solvents including dichloromethane could be used for the separations. Compared to the coated-type CSPs, the chemically bonded stationary phases enabled the enantioseparations of a larger number of racemates and exhibited enantioselectivity fully comparable to their counterparts prepared using porous silica as a support. However, the benefits of tailored macroporous polymer supports demonstrated earlier with brush-type CSPs did not enhance the performance of the chiral stationary phases prepared from cellulose-based selectors.

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…Seeded polymerizations seem to be suitable for production of SEC beads [427] since the pore size and pore size distribution can be easily controlled in the second swelling step. For HPLC columns, aerosol and precipitation [51,281] polymerizations are also available, together with seeded polymerizations [12,[68][69][428][429].…”

The Development and Application of Cellulose-Based Stationary Phases in Stereoselective Separation of Chiral Pesticides

“…Thus, the analytes have no access to the native surface of the support and non-specific interactions with the surface functionalities are not observed. [37].…”

Separation of Chiral Compounds on Polysaccharide Columns

“…The unmasked hydroxyl group at the cellulose was then linked to γ-aminopropylsilica gel via a diisocyanate spacer, and the corresponding materials were exhaustively capped with 3,5-dimethyl-or 3,5-dichlorophenylisocyanate to form the corresponding isocyanates. Several related protocols have been used by this or other groups [102][103][104] with some experimental modifications, one of them pursuing the immobilization of cellulose derivatives on polymer beads [105].…”