Catalysis direction selective asymmetric polymerization in chiral liquid crystal medium

A series of optically inactive aryl isocyanide derivatives were polymerized with an achiral nickel catalyst (Ni(II)Cl2) in a cholesteric liquid crystal (CLC) medium. The polymers synthesized from ortho-substituted phenyl isocyanide monomers in CLC phase show optical activity even though they have no chiral carbons. The Cotton effects of these polymers suggest that main chains of the polymers formed predominantly one-handed helical conformation. One-handed chiral environment in reaction state provided by CLC medium allows the formation of the polymers. The helical sense of the polymers is controllable by choice of (R)- or (S)-CLC as reaction solvent, though the monomer is same.

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