title: Folding Construction of a Pentacyclic Quadruply fused Polymer Topology with Tailored kyklo-Telechelic Precursors.
abstract: A pentacyclic quadruply fused polymer topology has been constructed for the first time through alkyne-azide addition (click) and olefin metathesis (clip) reactions in conjunction with an electrostatic self-assembly and covalent fixation (ESA-CF) process. Thus, a spiro-type, tandem tetracyclic poly(tetrahydrofuran), poly(THF), precursor having two allyloxy groups at the opposite positions of the four ring units was prepared by the click-linking of one unit of an eight-shaped precursor having alkyne groups at the opposite positions with two units of a single-cyclic counterpart having an azide and an alkene group at the opposite positions. Both are obtainable through ESA-CF. The subsequent metathesis clip-folding of the tetracyclic precursor could afford a pentacyclic quadruply fused polymer product, of "shippo" form, in 19% yield.
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8552, (Japan).
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Heguri
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8552, (Japan).
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8552, (Japan). ytezuka@o.cc.titech.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Tezuka
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis / Q000737:chemistry*; D000480:Alkynes / Q000138:chemical synthesis / Q000737:chemistry; D001386:Azides / Q000138:chemical synthesis / Q000737:chemistry; D057930:Click Chemistry; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000475:Alkenes; D000480:Alkynes; D001386:Azides; D005663:Furans; D011108:Polymers
keywords: click reactions; multicyclic polymers; olefin metathesis; polymer folding; topological polymer chemistry