title: Carbon Anionic Chiral Initiators for Asymmetric Anionic Polymerization of Achiral Isocyanates.
abstract: Novel optically active carbon anionic initiators bearing a chiral oxazole substituent on fluorene ring, (S)-1-(9H-fluoren-2-yl)-4-isopropyl-4, 5-dihydrooxazole lithium ((S)-1-FIDD-Li) and (S)-2-(9H-fluoren-2-yl)-4-isopropyl-4, 5-dihydrooxazole lithium ((S)-2-FIDD-Li), were synthesized. Anionic polymerizations of achiral polyisocyanates with the chiral initiators were investigated and optical rotation of the obtained polymers were attributed to asymmetric induction of the chiral initiators. The crowded substituent of initiator ((S)-2-FIDD-Li) seems to reduce the polymerizability of isocyanates and yet enhances the chiral induced ability in polymerization.
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department College of Chemistry, Institution Xiangtan University, Xiangtan University, Xiangtan, Hunan, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department College of Chemistry, Institution Xiangtan University, Xiangtan University, Xiangtan, Hunan, People's Republic of China.
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Department College of Chemistry, Institution Xiangtan University, Xiangtan University, Xiangtan, Hunan, People's Republic of China.
authors.forename: Sai
authors.initials: S
authors.lastname: Liang
keywords: asymmetric anionic polymerization; carbon anionic; chiral initiator; isocyanate derivatives; oxazole