title: Synthesis of eight-shaped poly(ethylene oxide) by the combination of Glaser coupling with ring-opening polymerization.
abstract: The eight-shaped poly(ethylene oxide) (PEO) is synthesized by a combination of Glaser coupling with ring-opening polymerization (ROP). Firstly, the star-shaped (PEO-OH)(4) is synthesized by ROP of ethylene oxide (EO) using pentaerythritol as an initiator and diphenylmethyl potassium (DPMK) as a deprotonated agent, and then the alkyne group is introduced onto the PEO arm-end to give (PEO-Alkyne)(4) in a NaH/tetrahydrofuran (THF) system. The intramolecular cyclization is carried out by a Glaser coupling reaction in a pyridine/CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) system at room temperature in an air atmosphere, and eight-shaped PEO was formed with high efficiency (almost 100%). The target polymers and intermediates were well characterized by SEC, MALDI-TOF MS, (1)H NMR and FT-IR in detail.
authors.affiliation: The Key Laboratory of Molecular Engineering of Polymer, State Education Ministry of China, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Wang
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Fan
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Yannan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Junlian
authors.initials: J
authors.lastname: Huang
mesh_terms: D002625:Chemistry, Organic / Q000379:methods*; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry; D058105:Polymerization; D011409:Propylene Glycols / Q000737:chemistry
chemical_list: D011409:Propylene Glycols; D011092:Polyethylene Glycols; C008783:pentaerythritol