Homopolymerization and copolymerization of N‐substituted maleimides with chiral anionic initiators

Novel optically active anionic initiators bearing a chiral oxazole substituent on the fluorene ring, (S)‐1‐(9H‐fluoren‐2‐yl)‐4‐isopropyl‐4,5‐dihydrooxazole lithium (Li‐(S)‐1‐FIDH) and (S)‐2‐(9H‐fluoren‐2‐yl)‐4‐isopropyl‐4,5‐dihydrooxazole lithium (Li‐(S)‐2‐FIDH), were prepared. Anionic homopolymerizations of achiral N‐substituted maleimide (RMI) with the chiral initiators were investigated. The optically active polymers obtained were attributed to asymmetric induction of the chiral initiators. The very crowded chiral initiator Li‐(S)‐1‐FIDH was found to play a better asymmetric induction role in the polymers than Li‐(S)‐2‐FIDH. Anionic copolymerization of (R)‐(+)‐N‐1‐phenylethyl maleimide and optically inactive RMI with Li‐(S)‐1‐FIDH were also studied. © 2014 Society of Chemical Industry