Optically active copolymers of N-(oxazolinyl)phenylmaleimides with methyl methacrylate: Synthesis and chiral recognition ability

The free radical copolymerization of three N-phenylmaleimides bearing a chiral oxazoline residue at ortho-position of the phenyl group (OPMI) with methyl methacrylate (MMA) was carried out in tetrahydrofuran by varying the molar ratio of the comonomers. The monomer reactivity ratios and Alfrey-Price Q-e values were determined. The data revealed that the monomer OPMI has a distinct tendency to cross-propagate and MMA is inclined to block formation. Meanwhile, the MMA co-units affected significantly the chiroptical property of resulted copolymers besides endowing them with a moderate film-forming ability. Poly(OPMI-co-MMA)s coated on macroporous silica were used as a high-performance liquid chromatography chiral selector, and the optical resolution performance was briefly evaluated toward some racemic compounds including amino- and hydroxy-acids as well as 1,1′-bi-2-naphthol. The observation indicated that the column combining MeOPMI/MMA copolymers with higher chiral component exhibits an extent of enantioselectivity in both normal and reversed-phase modes.