Asymmetric Anionic Oligomerization of N-Substituted Citraconimide with the Chiral Ligand-Organometal Complex

Abstract

Asymmetric anionic homopolymerizations of achiral N-substituted citraconimide (RCI, N-substituent: R = n-propyl (n-PrCI), n-butyl (n-BuCI), cyclohexyl (CHCI), phenyl (PhCI), benzyl (BzCI), 1-naphthyl (NCI), 4-(ethoxycarbonyl)phenyl (ECPCI), and a-methylbenzyl (MBzCI)) were performed with the chiral ligand-organometal complex in toluene or tetrahydrofuran (THF). The obtained oligo(RCI)s had very low molecular weights and relatively narrow polydispersity. The oligomers showed specific rotation ([ a ];~5 + 79.2° to-40.3°). Asymmetric induction took place on the polymer main chain and was confirmed by circular dichroism (CD) and GPC analysis using UV and polarimetric detectors.

Synthesis and polymerization of anthracene‐based itaconimides

“…Systematic studies on the reactivity of disubstituted ethylene monomers, especially of five‐membered cyclic imides, ie N ‐substituted maleimides and isomaleimides,1–14 citraconimides15–17 or itaconimides,18–21 in free radical and anionic polymerization have been carried out by a number of research groups. Polymerization takes place by opening of the double bond and head‐to‐tail coupling to obtain polymers of low molecular weight.…”