Ring-opening metathesis polymerization of amino acid-functionalized norbornene diamide monomers: Polymerization behavior and chiral recognition ability of the polymers

Amino acid-derived novel norbornene monomers were synthesized and polymerized with ruthenium catalysts. The polymerization rates were affected by the stereo structure of the monomers; exo,exo-NBL underwent ROMP faster to give the polymers in higher yields than the endo,exo-counterpart. The Grubbs 2nd generation catalyst was the most effective for the amino acid-based monomers. A polymer gel was synthesized by the copolymerization of exo,exo-NBL with 2.5 mol-% of bifunctional norbornene monomer. The gel adsorbed larger amounts of (R)-phenylalaninol and N-(benzyloxycarbonyl)alanine than those of the (S)-isomers.