title: Polycondensation of butenediol: synthesis of telechelic 2-butene-1,4-diol oligomers.
abstract: The catalytic condensation of cis-2-butene-1,4-diol with CpRu(MQA)(C(3)H(5)) (Cp = cyclopentadienyl, MQA = 4-methoxyquinoline-2-carboxylate) generates poly(2-butenediol), an unsaturated telechelic polyether diol with molecular weights between 400 and 4600 g/mol. This Ru(IV) allyl catalyst enchains 2-butene-1,4-diol primarily as the linear trans-2-butenyl ether (92%) along with vinyl branches (8%). These telechelic oligomers are useful chain extenders and macromonomers, as demonstrated by their use in the synthesis of poly(lactide)-b-poly(butenediol)-b-poly(lactide) triblock copolymers. Model studies support a proposed mechanism involving the formation of Ru(IV) allyl intermediates from allylic alcohols and chain growth by selective nucleophilic displacement at the terminus of the Ru(IV) allyl to generate trans-2-butenyl ether linkages.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Kiesewetter
authors.forename: Justin A
authors.initials: JA
authors.lastname: Edward
authors.forename: Hyunuk
authors.initials: H
authors.lastname: Kim
authors.forename: Robert M
authors.initials: RM
authors.lastname: Waymouth
mesh_terms: D002072:Butylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry
chemical_list: D002072:Butylene Glycols; D009942:Organometallic Compounds; C042544:penitricin C; D012428:Ruthenium