Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization

Abstract

Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]D = +61.0°, polymer [α]D = −3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010

Preparation of neutrally colorless, transparent polynorbornenes with multiple redox‐active chromophores via ring‐opening metathesis polymerization toward electrochromic applications

“…Ru (G2) exhibited good activity with respect to the polymerization of NBDTPAC8, but the obtained polymer had an uncontrolled molecular weight and broad PDI due to slower initiation and faster propagation rates 56. It is widely known that Ru (G3) exhibits better control due to faster initiation and inhibits side reactions such as back‐biting 57. We found that Ru (G3) promoted higher activity than Ru (G1) and Ru (G2).…”

Neutrally colourless, transparent and thermally stable polynorbornenes via ring-opening metathesis polymerisation for near-infrared electroactive applications

“…52 It is widely known that Ru (G3) exhibits better control due to faster initiation and inhibits side reactions like back-biting. 53 Ru (G3) promoted higher activity than Ru (G1) and Ru (G2) initiators. In Table 1, the number-average molecular weights of poly(NBDTPA) obtained by Ru (G1), Ru (G2) and Ru (G3) were, respectively, 1.33, 3.52 and 3.91 Â 10 5 with yields of 20, 80 and 85%.…”

Synthesis of polynorbornadienes by ring-opening metathesis polymerization and their saturated derivatives bearing various ester groups and carboxyl groups

“…However, when the amount of [Ru]-III catalyst was increased ([M]/[I] ratio = 200), the yield improved to 82% and a rather narrow polydispersity index of 1.05 was observed at −15 °C after 18 hours (entry 2, Table 1), indicating that corresponding polymer 1a was produced in a controlled living manner as has been reported by others. 3 f ,14 Therefore, this molar ratio (200) was adopted for the polymerization of the remaining monomers in Table 1.…”