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Living ring‐opening isomerization polymerization of 2,3,5,6‐tetrahydroimidazo[2,1‐ b ][1,3]oxazole with sulfonate initiators
Author(s) -
Miyamoto Masatoshi,
Watanabe Toshio,
Kimura Yoshiharu
Publication year - 1998
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19981001)199:10<2237::aid-macp2237>3.0.co;2-w
Subject(s) - cationic polymerization , polymerization , chemistry , oxazole , polymer chemistry , isomerization , ring opening polymerization , ionic polymerization , living anionic polymerization , photochemistry , anionic addition polymerization , polymer , radical polymerization , stereochemistry , organic chemistry , catalysis
The cationic ring‐opening isomerization polymerization of a bicyclic pseudourea, 2,3,5,6‐tetra‐hydroimidazo[2,1‐ b ][1,3]oxazole ( 1 ), was examined. The polymerization of 1 with methyl trifluoromethane‐sulfonate or p ‐toluenesulfonate proceeds even at −40°C and gives poly(1,3‐oxazolidin‐2‐one‐1,3‐diylethylene) ( 2 ) in high yield. Postpolymerization experiments revealed that the present polymerization proceeds in a “living” fashion. The mechanism of the polymerization was determined from in situ 1 H NMR measurements as well as kinetic analysis, which proved that the polymerization proceeds via ionic propagating species, although the apparent propagating species in the polymerization with methyl p ‐toluenesulfonate is covalent.