Asymmetric polymerization of N-1-anthrylmaleimide with diethylzinc-chiral ligand complexes and optical resolution using the polymer

Asymmetric anionic homopolymerizations of N-1-anthrymaleimide(1-AMI) were performed with diethylzinc (Et2Zn)-chiral ligand complexes to obtain optically active polymers. The optical activity of poly (1 -AMI) was influenced by polymerization conditions such as temperature, solvents and structures of chiral ligands. Poly(I-AMI) obtained with Et2Zn/(-)-2,2'-(1-ethylpropylidene)bis(4-benzyl-2-oxazoline) (Bnbox) in THF at 0degreesC showed the highest specific optical rotation ([alpha](25) = +92.5degrees). CD spectra of (+)-poly(1 -AMI) exhibited negative exciton chirality around D 230-300 nm, indicating that (1)Bbtransition moments of anthryl groups were twisted counterclockwise, Chiral recognition ability of poly(1-AMI) was investigated by H-1 NMR and HPLC, and the polymer coaled on silica gel optically resolved 1, 1'-bi-2 -naphthol.