A Reactive Helix: Synthesis, Chemical Modification, and Polymerization of an Optically Active Polymethacrylate

Abstract

1-(p-Vinylphenyl)dibenzosuberyl methacrylate (VDBSMA) having two reactive vinyl groups in a molecule was synthesized and polymerized using α,α′-azobis(isobutyronitrile) as a radical initiator and using the complexes of 9-fluorenyllithium with (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine, (−)-sparteine, and (S,S)-(+)-2,3-dimethoxy-1,4-bis(dimethylamino)butane as optically active anionic initiators. The free radical polymerization led to an insoluble material, indicating that both methacrylic and styrenic moieties participated in the polymerization and a cross-linked gel was produced. In contrast, the anionic polymerization proceeded exclusively through the addition reaction of methacrylic moiety leaving the styrenic vinyl group intact leading to soluble polymers. The resulting poly(VDBSMA)s having a polymethacrylate-type main-chain structure were highly isotactic and showed high optical activity and intense circular dichroism (CD) spectra, indicating that the polymers have a single-handed helical conformati...