Chiral Polymers

Kakuchi, Toyoji; Sakai, Ryosuke

doi:10.1002/0471440264.pst051

Cited by 3 publications

(3 citation statements)

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“…This is quite different from the general phenomenon with helical outwards that show definite opposite images for P-and M-helical morphologies transferred from the D-and Lform enantiomers. Both the PEI/D-tart@SiO 2 and SiO 2 /PEI-I-D (Figures 2a and 2b) exhibited nanofibrous morphologies with an average diameter of ca. 18 nm, indicating that the removal of tartaric acids residues by HCl (aq) did not damage the morphologies.…”

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confidence: 99%

Double Chiral Hybrid Materials: Formation of Chiral Phenolic Resins on Polyamine-associated Chiral Silica

et al. 2017

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Chiral SiO 2 nanofibers associated with polyamines on their surfaces could promote polymerization between resorcinol and formaldehyde on silica surface to give phenolic resins (RF). In this process, the chiral information was effectively transferred from SiO 2 to the final phenolic resins forming double chiral hybrid.Keywords: Double chiral hybrid | Chiral SiO 2 nanofiber | Chiral phenolic resinThe synthesis of chiral polymers with optical activity is of major importance because of their great demand in many areas like life sciences, pharmaceuticals, and optics.13 To achieve chirality in polymers during the polymerization process, various chiral sources have been employed for chiral transfer, which includes chiral organometallic complexes catalysts, chiral organic solvents, chiral polymeric templates, and even circular polarized light.4 On the other hand, some inorganic materials (e.g., porous SiO 2 , metal nanoparticles) have been widely used as supports for the load of chiral components to construct various heterogeneous catalysts, which possess advantages like easy separation and recycling of catalysts; however, most of these inorganic supports are achiral. 57 Based on the best of our understanding, to date, there are no reports on chiral polymerization using achiral catalyst supported by chiral inorganic supports.For a long time, the chiral inorganics are less of a concern compared with organics, despite the existence of natural inorganic crystals with intrinsically chiral crystal structures (e.g., quartz) or surfaces (e.g., Pt(643)). 8,9 However, in the past two decades, the research on the chiral transfer between organics and inorganics has gained increasing attention, and a series of synthetic inorganics have been endowed with chirality by molecular imprinting from small chiral organic molecules (on the molecular scale) or by copying the helical shapes (with helical pitch sizes over tens of nanometers) of organic templates.10,11 Interestingly, without the combination of external chiral components, it has been demonstrated that some natural and synthetic chiral inorganics could be directly applied to the enantioselective separation and synthesis of chiral organic small molecules (e.g., amino acids, glucoses).9,1215 Consequently, these achievements have opened a new avenue for chirality transfer from inorganics to organics. Recently, we reported a successful approach for the preparation of carbon nanotubes via carbonization of hybrid nanofibers of phenolic resins-coated silica which were synthesized by polymerization of resorcinol and formaldehyde on the polyamine (catalyst)-associated silica (template and support) nanofibers. 16 On the other hand, we also succeeded in the synthesis of chiral silica promoted by crystalline complexes self-assembled from polyethyleneimine (PEI) and enantiomeric tartaric acid (tart).17 By combining the above two achievements, herein, we attempted the synthesis of chiral phenolic resins (RF) by polymerization of resorcinol (R) and formaldehyde (F), employing the SiO 2 /PEI chi...

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confidence: 99%

Double Chiral Hybrid Materials: Formation of Chiral Phenolic Resins on Polyamine-associated Chiral Silica

et al. 2017

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“…The methods of introducing chirality into polymers can be sorted into three main categories by the type and position of the chiral source: [6] Much of this work focuses on pendant chirality (as, for example, obtained in polyisocyanides that form stereodefined helices with chiral pendant groups) [7] or conformational backbone chirality (as, for example, arising from helix sense‐selective polymerization). [ 1 , 6 , 8 ] The third, configurational main chain chirality (as, for example, obtained with isotactic polypropylene or chiral propylene oxide polymerizations), has received comparatively less attention [9] although the concepts are, of course, recurrent in sequence‐defined foldamer and DNA origami chemistry. Each of these classes of chirality has specific characteristics, and its own pros and cons.…”

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confidence: 99%

Configurationally Chiral SuFEx‐Based Polymers

et al. 2022

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Novel methods to make synthetic chiral polymers are highly desirable given their potential in a rapidly increasing number of bio‐inspired applications. The enantiospecific sulfur–fluorine exchange (SuFEx) reaction of chiral di‐sulfonimidoyl fluorides (di‐SFs) with diphenols, was used to produce high‐molecular‐weight chiral polymers with configurational backbone chirality. The resulting new class of polymers, polysulfonimidates, can be efficiently produced via this step‐growth mechanism for a wide range of di‐SFs and diphenols, yielding MnPS up to 283 kDa with a typical dispersity Đ around 1.6. The optical activity of the resulting chiral polymers is largely due to the intrinsic asymmetry of the S atoms (configurational chirality). Finally, the enantiospecificity (ee>98 %) of the polymerization reaction was demonstrated by the degradation of a disulfide‐containing polysulfonimidate. This novel route towards configurational main‐chain chirality opens up new approaches towards tailor‐made chiral polymers with precisely defined properties.

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“…Recently, helical polyacetylenes have attracted much attention, and fairly many examples have been reported. For examples, Akagi synthesized helical polyacetylene by using liquid crystalline media, 11 Yashima and coworkers have reported many interesting results on induced helical polymers, 12 Aoki has found helix-sense-selective polymerization (HSSP) of 3,4,5-trisubstituted phenylacetylene having two hydroxyl groups at m,m positions, 13 Tang's and Kakuchi's groups studied helical structures of poly(phenylacetylene)s having amino acid moieties, 14,15 and Sanda and Masuda's group synthesized various helical substituted polyacetylenes. 16 HSSP is a useful method of synthesizing optically active polymers in which chirality is solely based on the main chain conformation (helicity) and no chiral carbons are required in the monomer at all.…”

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Novel isolated, L-amino acid-ligated rhodium catalysts that induce highly helix-sense-selective polymerization of an achiral 3,4,5-trisubstituted phenylacetylene

Jia

Shi

et al. 2016

J. Polym. Sci. Part A: Polym. Chem.

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Two novel chiral well‐defined rhodium complexes, Rh(cod)(L‐Phe) (cod = 1,5‐cyclooctadiene, Phe = phenylalanine) and Rh(cod)(L‐Val) (Val = valine) were synthesized, isolated by recrystallization, and characterized. The helix‐sense‐selective polymerization (HSSP) of an achiral 3,4,5‐trisubstituted phenylacetylene, p‐dodecyloxy‐m,m‐dihydroxyphenylacetylene (DoDHPA) was examined by using the two Rh complexes as catalysts. These catalysts provided high molecular weight polymers (Mw 28 × 104−45 × 104) in about 40%–85% yields. The resulting polymers exhibited a bisignated CD signal at about 300 nm and a broad signal around 470 nm, indicating that they have preferential one‐handed helical structure. The present catalysts achieved larger molar ellipticity up to [θ]310 = 13.0 × 104 deg cm2/dmol than those with binary chiral catalytic systems, [Rh(cod)Cl]2/(L‐phenylalaninol), [Rh(cod)Cl]2/(L‐valinol), and [Rh(nbd)Cl]2/(R)‐PEA. All these results manifest that the present, well‐defined Rh complexes serve as excellent catalysts for the HSSP of DoDHPA. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2346–2351

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Chiral Polymers

Cited by 3 publications

References 265 publications

Double Chiral Hybrid Materials: Formation of Chiral Phenolic Resins on Polyamine-associated Chiral Silica

Double Chiral Hybrid Materials: Formation of Chiral Phenolic Resins on Polyamine-associated Chiral Silica

Configurationally Chiral SuFEx‐Based Polymers

Novel isolated, L-amino acid-ligated rhodium catalysts that induce highly helix-sense-selective polymerization of an achiral 3,4,5-trisubstituted phenylacetylene

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