Synthesis of Polymeric Topological Isomers through Double Metathesis Condensation with H‐Shaped Telechelic Precursors

Tezuka, Yasuyuki; Ohashi, Fuminobu

doi:10.1002/marc.200400663

Cited by 40 publications

(43 citation statements)

References 22 publications

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“…[100][101][102][103][104] Cationic polymerization of THF followed by incorporation of two allyl-ether endgroups yielded suitable linear precursors. 100,101 Scheme 25 illustrates the synthesis of a ''defect-free'' cyclic poly THF.…”

Section: -1351-70mentioning

confidence: 99%

“…100,101 Scheme 25 illustrates the synthesis of a ''defect-free'' cyclic poly THF. 101 This approach was then successfully extended to syntheses of more complex architecture such as manacleshaped or b-shaped (bicyclic) poly(tetrahydrofuran)s. 102,103 Finally, cyclic diblock copolymers were prepared from methyl methacrylate and n-butylmethacrylate. These monomers were sequentially copolymerized by the ATRP method in such a way that A-B-A triblock copolymers having two vinyl endgroups were obtained (Scheme 26).…”

Section: -1351-70mentioning

confidence: 99%

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Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

399

442

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Syntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun-shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring-ring equilibration, or ring-expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed.

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Section: -1351-70mentioning

confidence: 99%

Section: -1351-70mentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

399

442

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“…These polymeric topological isomers, as well as a pair of linear and ring polymers, were separated by reversed phase chromatography under critical and near-critical interaction conditions. [18][19][20][21][22] The chemical assignment of the polymeric topological isomers with either y or manacle construction has subsequently been performed by using polymers containing a cleavable olefinic group in a backbone segment (Scheme 3a). 23 Thus, a pair of y-and manacle-shaped polymeric isomers with a metathesis-cleavable olefinic unit at the specified position were synthesized by the ESA-CF process by using a linear precursor with an inner olefinic group at the center position.…”

Section: Geometrical Classification and Isomeric Properties Of Cyclicmentioning

confidence: 99%

“…20 Alternatively, a pair of dicyclic polymeric topological isomers with y and manacle constructions were formed through the metathesis clip process using an H-shaped precursor with allyloxy end groups at each chain end (Scheme 10). 21 The selective construction of a dicyclic, manacle-shaped polymer topology was achieved through the click coupling of a bifunctional linear telechelic precursor containing azide groups with a cyclic polymer precursor bearing an alkyne group obtainable through the ESA-CF protocol (Scheme 10). 54 Likewise, a bridged-tricyclic three-way paddle-shaped polymer was obtained by the relevant click coupling reaction between a star-shaped trifunctional precursor containing azide groups with a cyclic polymer precursor bearing an alkyne group (Scheme 10).…”

Section: Topological Polymer Chemistry Y Tezukamentioning

confidence: 99%

Topological polymer chemistry for designing multicyclic macromolecular architectures

Tezuka

2012

Polym J

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The geometrical conception and current synthetic challenges of topological polymer chemistry have been reviewed. On the basis of the systematic classification and isomeric properties of polymer chain topologies, a variety of novel multicyclic macromolecular constructions have now been rationally designed and subsequently realized by intriguing synthetic protocols. In particular, cyclic and multicyclic polymer products are effectively produced by an electrostatic polymer self-assembly of telechelic precursors that contain cyclic ammonium salt groups accompanying polyfunctional carboxylate counteranions and the subsequent covalent conversion through the ring-opening or through the ring-emitting reaction of the cyclic ammonium salt groups by carboxylate counteranions (Electrostatic Self-assembly and Covalent Fixation (ESA-CF) process). Furthermore, the ESA-CF process, in conjunction with effective linking/cleaving chemistry (including the metathesis condensation (clip) and alkyne-azide addition (click) reactions), has been demonstrated as a new synthetic protocol for unprecedented multicyclic macromolecular topologies.

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“…26 The metathesis condensation has also been applied with an H-shaped precursor having allyloxy end groups at each chain end, to produce dicyclic polymeric topological isomers having q and manacle constructions (Scheme 10). 27 Moreover, an 8-shaped kyklo-telechelic precursor having two allyl groups at opposite positions has been prepared by the electrostatic self-assembly and covalent fixation with a self-assembly consisting of two units of a cationic linear precursor having an allyl group and tetracarboxylate counteranion, and subjected to the metathesis condensation to construct a polymeric d-graph having a doubly-fused tricyclic topology (Scheme 10). …”

Section: Polymer Cyclization Through Rcm Processmentioning

confidence: 99%

Topological Polymer Chemistry in Pursuit of Elusive Polymer Ring Constructions

Adachi

Tezuka

2009

J. Synth. Org. Chem. Jpn.

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Current challenges and future perspectives of topological polymer chemistry have been reviewed. A variety of novel cyclic and multicyclic macromolecular topologies has now been realized by intriguing synthetic protocols. In particular, the electrostatic polymer self-assembly of telechelic precursors having cyclic ammonium salt groups accompanying polyfunctional carboxylate counteranions has been exploited in dilution to produce topologically significant, non-covalent constructions of a dynamic nature. The subsequent covalent conversion through the ring-opening or through the ring-emitting reaction of cyclic ammonium salt groups by carboxylate counteranions provides cyclic and multicyclic polymer products effectively. Furthermore, the metathesis condensation process with functional cyclic polymer precursors has been demonstrated as a promising synthetic means to construct a variety of complex polymer topologies. Scheme 1. Single and multicyclic polymer topologies (ring family tree).tive properties in comparison with conventional linear or branched polyethylenes. 7a The "end-biting" chain transfer to eliminate the initiator species is a key to producing stable ring polymers. However, the chain transfer occurs concurrently during the propagation, and the chain length distribution (MWD) of the polymer products could not be controlled rigorously. By this ring-expansion process using a bulky, dendronized monomer, a ring-shaped nano-object has also been produced. 7e Ring poly(sulfide)s, free of the initiator fragment and having controlled size distributions have also been reported, in which the repetitive insertion of thiirane, a three-membered cyclic sulfide monomer into the thioester unit of a cyclic initiator proceeds with the concurrent chain transfer by intermolecular ester exchange reactions.7f More recently, ring polyesters with narrow size distributions have been obtained by a zwitterionic ring-opening polymerization of cyclic lactones and lactides with an N-heterocyclic carbene initiator (Scheme 2).7g-i In this process, the "end-biting" chain transfer is assumed to take place after the rapid propagation to eliminate the initiator species. Furthermore, ring-expansion polymerization has been combined with the end-linking reaction for the practical synthesis of ring polymers of high molar mass (Scheme 2). 10Thus, a cyclic initiator of stannous dialkoxide has been employed for the ring-opening polymerization of e-caprolactone. By taking advantage of the living nature of this process, a few units of a photo-crosslinkable, acrylate-functionalized e-caprolactone derivative have subsequently been introduced. Thereafter the intramolecular photo-crosslinking of acrylic groups has been conducted under dilution, and the stannous dialkoxide initiator fragment has finally been removed by hydrolysis, to produce ring polymers free of the initiator fragments.10a By this process, a twin-tail tadpole polymer comprised of a ring and two outward branch segments, has also been prepared by the re-initiation of ring-ope...

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Synthesis of Polymeric Topological Isomers through Double Metathesis Condensation with H‐Shaped Telechelic Precursors

Cited by 40 publications

References 22 publications

Cyclic polymers: Synthetic strategies and physical properties

Cyclic polymers: Synthetic strategies and physical properties

Topological polymer chemistry for designing multicyclic macromolecular architectures

Topological Polymer Chemistry in Pursuit of Elusive Polymer Ring Constructions

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