Thorpe‐Ingold Effect on the ATRP‐Induced Cyclopolymerization of Bismethacrylate Tethered by a Substituted Silylene Moiety

Hu, Ziqiang; Xu, Yongping; Wu, Di; Li, Bin; Huang, Yuan; Jiang, Jianxiong; Lai, Guoqiao; Luh, Tien‐Yau

doi:10.1002/macp.201100530

Cited by 9 publications

(9 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…67 The capability of generating even larger rings in the repeating units has been recently further extended. Hu et al 68 reported the cyclopolymerization using ATRP of dialkylsilylene-tethered bismethacrylates 17, generating fourteen-membered cyclic units. The polymerizations were carried out in very diluted conditions (250 μM in DMSO) using standard ATRP conditions.…”

Section: Acrylate Based-systems Providing Larger Ring Formationmentioning

confidence: 99%

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

2018

View full text Add to dashboard Cite

Monomers possessing two functionalities suitable for polymerization are often designed and utilized in syntheses directed to the formation of cross-linked macromolecules. In this review, we give an account of recent developments related to the use of such monomers in cyclopolymerization processes, in order to form linear, soluble macromolecules. These processes can be activated by means of radical, ionic, or transition-metal mediated chain-growth polymerization mechanisms, to achieve cyclic moieties of variable ring size which are embedded within the polymer backbone, driving and tuning peculiar physical properties of the resulting macromolecules. The two functionalities are covalently linked by a "tether", which can be appropriately designed in order to "imprint" elements of chemical information into the polymer backbone during the synthesis and, in some cases, be removed by postpolymerization reactions. The two functionalities can possess identical or even very different reactivities toward the polymerization mechanism involved; in the latter case, consequences and outcomes related to the sequence-controlled, precision synthesis of macromolecules have been demonstrated. Recent advances in new initiating systems and polymerization catalysts enabled the precision syntheses of polymers with regulated cyclic structures by highly regio- and/or stereoselective cyclopolymerization. Cyclopolymerizations involving double cyclization, ring-opening, or isomerization have been also developed, generating unique repeating structures, which can hardly be obtained by conventional polymerization methods.

show abstract

Section: Acrylate Based-systems Providing Larger Ring Formationmentioning

confidence: 99%

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

2018

View full text Add to dashboard Cite

show abstract

“…These monomers are different from the dialkylsilylene-spaced divinyl monomers. The two vinyl groups in the latter are forced into closer proximity due to the so-called geminal Thorpe–Ingold effect . Contrary to those divinyl monomers reported in the literature for large-ring cyclopolymerization where the two vinyl groups are oriented by the conformational rigidity (e.g., chiral control and steric hindrance, etc.…”

Section: Resultsmentioning

confidence: 98%

Cyclopolymerization of Disiloxane-Tethered Divinyl Monomers To Synthesize Chirality-Responsive Helical Polymers

Zhao

et al. 2016

Macromolecules

View full text Add to dashboard Cite

Synthetic polymers mimicking the stimuli-responsive coiled-coil structures of naturally occurring macromolecules such as motor proteins remain challenging. Here we report that chirality switchable quasi-double helical polymers can be synthesized by the free radical cyclopolymerization of the tetramethyldisiloxane-tethered divinyl monomers. Two cyclopolymers (pbSt and pbMA) are obtained in this work, which in solid state are helical polymers investigated by both ECD and VCD. According to VCD analysis, the C–H deformation modes including C–H bending (mode I) and C–H rocking (mode II) in the main-chain helix show strong signals in VCD spectra and the plots of the division of VCD by IR, which have different responses to solvation histories or thermal treatment compared with other vibrational signals arising from side rings (especially signals from tetramethyldisiloxane groups). After thermal treatment, all the side-ring VCD signals of both pbSt and pbMA are inverted, while the VCD signals from mode II of the main chain are unchanged. In cast films from chloroform solutions, pbSt shows only and inverted VCD signals arising from mode I and mode II of the main-chain helix, but not any VCD signals from side rings. Ab initio quantum calculation reveals that the change in the orientation of side-ring distortion against the main chain may account for the inversion of side-ring VCD signals. The responses of the experimental VCD spectra of the cyclopolymers can thus be rationalized based on the quantum calculation results. The main-chain helices of the cyclopolymers remained unchanged, while the side rings changed their distortion orientation during thermal treatment. In cast films from chloroform solutions, the polymer main-chain helix was inverted, hence inverted main-chain VCD; while the side rings might be randomly distorted, causing loss of VCD from side rings. Overall, the main-chain helices and side-ring pseudohelices can be switched independently. This work presents the first example that a single macromolecule can display such (quasi-)double-helical conformation. Besides the theoretical value, this kind of chirality switchable quasi-double-helical polymer may find application in asymmetric catalyst, smart molecular devices, etc.

show abstract

“…In template-assisted long-range macrocyclization systems, intramolecular macrocyclization is achieved through judicious template design (Scheme B). Typical examples of these templates include 1,2-disubstituted cyclohexane, gem -disubstituted silyl ester, calixarene, and crown ether, , where the rigidity of the templates or their abilities to establish ligand–metal coordination are essential for the intramolecular ring-closing. In both rRCCP systems, a nonoptimal spacer or template between the two CC double bonds in a monomer can lead to undesired 1,2-polymerization, in which only one CC double bond participates in chain propagation, leaving unreacted dangling olefins as potential cross-linking sites detrimental to polymerization control.…”

Section: Radical Cascade Polymerizationmentioning

confidence: 99%

“…In both rRCCP systems, a nonoptimal spacer or template between the two CC double bonds in a monomer can lead to undesired 1,2-polymerization, in which only one CC double bond participates in chain propagation, leaving unreacted dangling olefins as potential cross-linking sites detrimental to polymerization control. It is also noteworthy that rRCCP can greatly benefit from the recent developments of controlled radical polymerization techniques, including atom transfer radical polymerization (ATRP), ,, reversible addition–fragmentation chain-transfer polymerization (RAFT), ,, and nitroxide-mediated polymerization (NMP) . These developments allow for precise control over polymerization rate, dispersity, architecture, and sequence.…”

Section: Radical Cascade Polymerizationmentioning

confidence: 99%

Cascade Reactions in Chain-Growth Polymerization

et al. 2020

View full text Add to dashboard Cite

While the design and implementation of cascade reactions in organic chemistry and enzymatic biosynthesis flourished in the past decades, cascade reactions in polymerization remain an emerging concept with exciting opportunities. Cascade polymerization techniques can be used to generate polymers in which unique structures and functionalities are incorporated in the backbone of polymers, making them powerful tools to address the ever-increasing demand for new materials with improved functionality and sustainability. This Perspective highlights existing strategies for chain-growth cascade polymerizations following radical, ionic, nucleophilic, and transition metal catalysis mechanisms, with a focus on the design principle and reaction mechanism. Collectively, recent work illustrates the considerable potential and predicts future developments of chain-growth cascade polymerization, an active research field at the intersection of polymer science and organic chemistry.

show abstract

Thorpe‐Ingold Effect on the ATRP‐Induced Cyclopolymerization of Bismethacrylate Tethered by a Substituted Silylene Moiety

Cited by 9 publications

References 78 publications

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

Cyclopolymerizations: Synthetic Tools for the Precision Synthesis of Macromolecular Architectures

Cyclopolymerization of Disiloxane-Tethered Divinyl Monomers To Synthesize Chirality-Responsive Helical Polymers

Cascade Reactions in Chain-Growth Polymerization

Contact Info

Product

Resources

About