Contribution to the Proceedings of the 22nd International Symposium on Chirality [ISCD 22]
Regular Article/Contribution to the Proceedings of the 22nd International Symposium on Chirality [ISCD 22]
Asymmetric polymerizations of chiral 4-benzyl-2-ethynyloxazoline with rhodium catalyst and chiroptical properties of the polymers†
Version of Record online: 28 APR 2011
Copyright © 2011 Wiley Periodicals, Inc.
Special Issue: Proceedings from the 22nd International Symposium on Chirality, Sapporo, Japan, 2010
Volume 23, Issue 1E, pages E43–E51, 2011
How to Cite
Onimura, K., Shintaku, K., Rattanatraicharoen, P., Yamabuki, K. and Oishi, T. (2011), Asymmetric polymerizations of chiral 4-benzyl-2-ethynyloxazoline with rhodium catalyst and chiroptical properties of the polymers. Chirality, 23: E43–E51. doi: 10.1002/chir.20959
- Issue online: 24 OCT 2011
- Version of Record online: 28 APR 2011
- Manuscript Accepted: 4 FEB 2011
- Manuscript Received: 30 OCT 2010
Choose one or more boxes to highlight terms.
- coordination polymerization;
- optically active polymer;
- helical polymer;
- conjugated polymer
Optically active 4-alkyl-2-ethynyloxazoline derivatives (BnEOx) were polymerized with rhodium catalysts. The polymerization in toluene produced polymer with the highest absolute values of specific rotation ([α]D = −77.3°). The yields, molecular weights, and specific rotations of poly(BnEOx)s were influenced by polymerization conditions. The copolymerization with phenylacetylene (PA) was effective to increase the molecular weight of the copolymer. It is interesting to note that the copolymers exhibited positive specific rotations ([α]D = +4.7° to +62.5°) despite the fact that [α]Ds of BnEOx and the homopolymer are negative sign. The chiroptical properties were investigated by the chiral/achiral copolymerization of BnEOx with PA. The copolymerizations of BnEOx with PA gave copolymers containing higher order structure such as one-handed helical conformation. Furthermore, induced Cotton effects were observed in the π–π* transition region of conjugated main chain depending a complex of these polymers with zinc triflate salt in tetrahydrofuran solution, indicating the formation of chiral supramolecular aggregates. Chirality, 2011. © 2011 Wiley Periodicals, Inc.