Chromatographic enantioseparation by poly(biphenylylacetylene) derivatives with memory of both axial chirality and macromolecular helicity

Ishidate, Ryoma; Ikai, Tomoyuki; Kanoh, Shigeyoshi; Yashima, Eiji; Maeda, Katsuhiro

doi:10.1002/chir.22687

Cited by 31 publications

(58 citation statements)

References 37 publications

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“…On the other hand, introduction of two ester (acetyloxy) groups at the 2- and 2′-positions of the biphenyl pendant instead of two OMOM groups resulted in destabilization of the helicity memory. Although a similar helicity induction and memory effect were also observed for 47 , the helicity memory of 47b disappeared more quickly than that of 34 in methylcyclohexane [103]. However, in the solid state, the helicity memory of 47b was maintained for an extremely long time, at least for 1 month at 25 °C as confirmed by no detectable decrease in the ICD intensity, which enabled us to utilize 47 as a CSP for HPLC.…”

Section: Application Of Helical Polyacetylenes As Chiral Materialssupporting

confidence: 53%

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Maeda

Yashima

2017

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Construction of predominantly one-handed helical polyacetylenes with a desired helix sense utilizing noncovalent chiral interactions with nonracemic chiral guest compounds based on a supramolecular approach is described. As with the conventional dynamic helical polymers possessing optically active pendant groups covalently bonded to the polymer chains, this noncovalent helicity induction system can show significant chiral amplification phenomena, in which the chiral information of the nonracemic guests can transfer with high cooperativity through noncovalent bonding interactions to induce an almost single-handed helical conformation in the polymer backbone. An intriguing “memory effect” of the induced macromolecular helicity is observed for some polyacetylenes, which means that the helical conformations induced in dynamic helical polyacetylene can be transformed into metastable static ones by tuning their helix-inversion barriers. Potential applications of helical polyacetylenes with controlled helix sense constructed by the “noncovalent helicity induction and/or memory effect” as chiral materials are also described.

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Section: Application Of Helical Polyacetylenes As Chiral Materialssupporting

confidence: 53%

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Maeda

Yashima

2017

Top Curr Chem (Z)

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“…On the other hand, introduction of two ester (acetyloxy) groups at the 2-and 2 0positions of the biphenyl pendant instead of two OMOM groups resulted in destabilization of the helicity memory. Although a similar helicity induction and memory effect were also observed for 47, the helicity memory of 47b disappeared more quickly than that of 34 in methylcyclohexane [103]. However, in the solid state, the helicity memory of 47b was maintained for an extremely long time, at least for 1 month at 25°C as confirmed by no detectable decrease in the ICD intensity, which enabled us to utilize 47 as a CSP for HPLC.…”

Section: Structuresupporting

confidence: 62%

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Maeda

Yashima

2017

Topics in Current Chemistry Collections

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Construction of predominantly one-handed helical polyacetylenes with a desired helix sense utilizing noncovalent chiral interactions with nonracemic chiral guest compounds based on a supramolecular approach is described. As with the conventional dynamic helical polymers possessing optically active pendant groups covalently bonded to the polymer chains, this noncovalent helicity induction system can show significant chiral amplification phenomena, in which the chiral information of the nonracemic guests can transfer with high cooperativity through noncovalent bonding interactions to induce an almost single-handed helical conformation in the polymer backbone. An intriguing ''memory effect'' of the induced macromolecular helicity is observed for some polyacetylenes, which means that the helical conformations induced in dynamic helical polyacetylene can be transformed into metastable static ones by tuning their helix-inversion barriers. Potential applications of helical polyacetylenes with controlled helix sense constructed by the ''noncovalent helicity induction and/or memory effect'' as chiral materials are also described.

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“…In this case, a large amount of chiral guests was necessary to control the helixsense. [26][27][28] In addition, our group has also developed a foldamer based switchable CSP, which shows reversible coil-to-helix transition in the solid state. 29 These two macromolecular structures shown different chiral recognition ability depending on their two different conformations (helix and random states) of the foldamer.…”

Section: Introductionmentioning

confidence: 99%

Three-State Switchable Chiral Stationary Phase Based on Helicity Control of an Optically Active Poly(phenylacetylene) Derivative by Using Metal Cations in the Solid State

et al. 2019

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An unprecedented three-state switchable chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC) was developed by using a helical poly(phenylacetylene) bearing a chiral (R)-α-methoxyphenylacetic acid residue as the pendant (poly-1). The left-and right-handed helical conformations were induced in poly-1-based CSP upon coordination with a catalytic amount of soluble sodium and cesium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate salts (MBArF), respectively, which are soluble in the HPLC conditions [hexane−2-propanol (95:5, v/v)]. The switch between the two different helical states of poly-1 can be easily done by rinsing the poly-1-based CSP with MeOH and the subsequent addition of the proper MBArF salt. By using this dynamic helical CSP, we demonstrated how changes on the orientation of secondary structure of a chiral polymer can alter and even invert the elution order of the enantiomers. This study was done without adding chiral additives or changing the mobile phase which could produce changes on the retention times making more difficult to extract the role of the secondary structure during the chiral recognition process. Figure 1. Schematic illustration of macromolecular helicity modulation in poly-1 through conformational switching of the MPA pendants using metal cations in solution. ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website at DOI: XXXXXXXXXX. Materials and methods and supporting data (PDF)

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Chromatographic enantioseparation by poly(biphenylylacetylene) derivatives with memory of both axial chirality and macromolecular helicity

Cited by 31 publications

References 37 publications

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Helical Polyacetylenes Induced via Noncovalent Chiral Interactions and Their Applications as Chiral Materials

Three-State Switchable Chiral Stationary Phase Based on Helicity Control of an Optically Active Poly(phenylacetylene) Derivative by Using Metal Cations in the Solid State

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