Optically Active Polymer Synthesis by Diels−Alder Polymerization with Chirally Modified Lewis Acid Catalyst

A series of copolymers have been synthesized by Diels−Alder polymerization of bisdienophile monomer with bisdiene monomer. Bismaleimides ( 1 ) and bis(α,β-unsaturated ester)s ( 4 ) were prepared and used as bisdienophile monomer. Furfuryl and butadienyl moieties were chosen as the diene part of the bisdiene monomers ( 2, 5 ). Repetitive Diels−Alder reactions between these monomers in the presence of Lewis acid catalyst yielded alternative Diels−Alder polymers ( 6, 12, 13, 15 ). On the basis of these results, asymmetric Diels−Alder polymerization was investigated. The use of enantiopure Lewis acid catalysts ( 7 − 10 ) in the Diels−Alder polymerization of above monomers resulted in the formation of optically active polymers having the asymmetric carbons in their main chain.