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Published October 19, 1999 | public
Journal Article

Synthesis of Functionalized Polyethers by Ring-Opening Metathesis Polymerization of Unsaturated Crown Ethers


A variety of polyethers were synthesized by a tandem approach incorporating ring-closing metathesis (RCM) followed by ring-opening metathesis polymerization (ROMP) using RuCl_2(=CHPh)(PCy_3)_2 (1) as an initiator. Unsaturated crown ether monomers, including a 12-crown-4 analogue (3), a benzocrown ether (8), and a benzocrown ether with a pendent phenylalanine methyl ester (9), were synthesized in good yields using a lithium ion as a template and 1 as a catalyst for RCM. Saponification of 9 afforded the benzocrown phenylalanine carboxylic acid monomer 10. The ROMP of 3, 8, and 9 with 1 as an initiator yielded the homopolymers 11, 12e, and 13e, respectively. The relative concentrations of 3 to 1 were varied to produce 11 with a wide range of molecular weights (M_n from 10 900 to 206 300). Hydrogenation of 11 proceeded quantitatively to yield a saturated polyether. Monomers 8 and 9 were copolymerized with 3 to generate polymers 12a−d and 13a−d, respectively. The copolymer composition corresponded to the feed ratio of the monomers. Crown ether 10 was copolymerized with 3 at a low feed ratio to form the corresponding polyether with pendent amino acids.

Additional Information

© 1999 American Chemical Society. Received May 13, 1999; Revised Manuscript Received August 17, 1999. The authors are grateful to the National Science Foundation (Grant CHE-9809856) and the National Institute of Health (Grant GM 3133213) for funding of this research. Dr. Michael J. Marsella is thanked for his contributions to the initial parts of this work. Dr. Delwin L. Elder and Dr. David M. Lynn are thanked for their critical reading of this manuscript.

Additional details

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October 18, 2023