Synthesis of Chiral, Optically Active Copolymers

Abstract

Optically active polymers are synthesized either by polymerization of optically active monomers or by asymmetric polymerization of optically inactive monomers. The latter type of polymerization can be further classified into three categories, namely, (i) asymmetric synthesis polymerization, (ii) helix-selective polymerization, and (iii) enantiomer-selective polymerization (kinetic resolution of racemic monomer). Asymmetric synthesis polymerization is the reaction that produces polymers with configurational chirality in the main chain, starting from prochiral monomers. Chiral induction is achieved by selective attack of the growing species on a monomer at one of the enantiofaces of unsaturated bonding. The olefin/CO alternating copolymerization serves as a unique example of the asymmetric synthesis polymerization, as follows.