Enantioseparation of 1-(p-bromophenyl)ethanol by crystallization of host–guest complexes with permethylated β-cyclodextrin: crystal structures and mechanisms of chiral recognition

Grandeury, Arnaud; Petit, Samuel; Gouhier, Géraldine; Agasse, Valerie; Coquerel, Gérard

doi:10.1016/s0957-4166(03)00360-4

Cited by 26 publications

(37 citation statements)

References 34 publications

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“…Possible techniques are liquid chromatography (e.g., SMB-chromatography as depicted before), chiral membrane separation, 22,23 or crystallization with the help of supramolecular complexes. 24,25 The enantiomeric enrichment to be achieved is determined by the position of the \eutectic line" in the ternary solubility phase diagram (see Fig. 2, Eut), which is frequently identical to the eutectic composition in the binary chiral system.…”

Section: Concept For Coupling a Preliminary Enrichment Step And Prefementioning

confidence: 99%

Application of preferential crystallization to resolve racemic compounds in a hybrid process

2006

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The application of preferential crystallization is at present limited to conglomerate forming systems, which cover only a minor part of chiral substances. In this paper, a hybrid process is proposed that extends the applicability of the preferential crystallization principle to the more common racemic compound forming systems. It comprises a preliminary (e.g., chromatographic) enantiomeric enrichment step and preferential crystallization to finally produce the desired pure enantiomer(s). The applicability of preferential crystallization to racemic compounds is demonstrated on the example of mandelic acid as a model system. Direct monitoring of the separation progress is performed using combined online polarimetry and online density measurements. A cyclic crystallization process, which provides alternating the pure mandelic acid enantiomer and the racemic compound, is feasible and allows the resolution of rac-mandelic acid as part of the proposed hybrid approach.

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Section: Concept For Coupling a Preliminary Enrichment Step And Prefementioning

confidence: 99%

Application of preferential crystallization to resolve racemic compounds in a hybrid process

2006

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“…The crystal packing of 4CPA/TMCD is unique. The complex crystallizes in the space group P2 1 , like the inclusion compounds of indole-3-butyric acid, 2,4-dichlorophenoxyacetic acid and 1-(p-bromophenyl) ethanol (Grandeury et al, 2003) in TMCD, but it has different unit-cell parameters (Table 4). Its crystal axes do not differ considerably from those of the TMCD complexes with 1,7-dioxaspiro[5.5]undecane (Makedonopoulou et al, 2001), methylcyclohexane (Rontoyianni et al, 1998;Cardinael et al, 2001) and l-menthol (Caira et al, 1996; see also Table 4), crystallizing in the space group P2 1 2 1 2 1 and the volume of its asymmetric unit being 4133 Å 3 , which is approximately double the volumes of the three complexes ranging between 2037 and 2144 Å 3 .…”

Section: Cpa/tmbcdmentioning

confidence: 99%

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

Tsorteki

Bethanis

Pinotsis

et al. 2005

Acta Crystallogr Sect B

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The crystal structures of 4-chlorophenoxyacetic acid (4CPA) included in beta-cyclodextrin (beta-CD) and heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TMbetaCD) have been studied by X-ray diffraction. The 4CPA/beta-CD complex crystallizes as a head-to-head dimer in the space group C2 in the Tetrad packing mode. The packing modes of some beta-CD dimeric complexes, having unique stackings, are also discussed. The 4CPA/TMbetaCD inclusion complex crystallizes in the space group P2(1) and its asymmetric unit contains two crystallographically independent complexes, complex A and complex B, exhibiting different conformations. The host molecule of complex A is significantly distorted, as a glucosidic residue rotated about the O4'-C1 and C4-O4 bonds forms an aperture where the guest molecule is accommodated. The phenyl moiety of the guest molecule of complex B is nearly perpendicular to the mean plane of the O4n atoms. The conformations of the guest molecules of the two complexes are similar. The crystal packing consists of antiparallel columns as in the majority of the TMbetaCD complexes published so far.

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“…Compared to the separation figure on the b-CD column, it can be seen that the PM-b-CD column has better enantioselectivities and higher resolution. The poor ability of native CDs to achieve enantioseparation of guest compounds was supposed to result from the molecular rigidity of these hosts, whereas the loss of intramolecular hydrogen bondings between methoxyl groups in PM-b-CD is assumed to improve its capability for chiral recognition [17]. Influence of Column Temperature…”

Section: Influence Of Content Of Methanol In Mobile Phasementioning

confidence: 99%

Experimental and Theoretical Studies on the Enantioseparation and Chiral Recognition of Mandelate and Cyclohexylmandelate on Permethylated β-Cyclodextrin Chiral Stationary Phase

Shi

Ding

2011

Chromatographia

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Enantioseparations of methyl mandelate (MMA) and methyl a-cyclohexylmandelate (MCHMA) on permethylated b-cyclodextrin (PM-b-CD) chiral stationary phase were explored in detail using high-performance liquid chromatography. The influence of the concentration of organic modifiers, along with the column temperature, was studied. In addition, the thermodynamics parameters of the enantioseparations were determined to discuss driven power in the process of enantioseparations. In addition, host-guest complexation of PM-b-CD with MMA enantiomers was simulated by quantum mechanics PM3 method for understanding the chiral recognition mechanism. The experimental results showed that the retention factor (k), separation factor (a), and resolution factor (Rs) for MMA and MCHMA resolved on the PM-b-CD column all generally decreased with the increase of methanol content, which indicated that the main chiral recognition mechanism is that the hydrophobic portions of MMA and MCHMA are included in the hydrophobic cavity of PM-b-CD to form inclusion complexes. In addition, there is an excellent linear relationship between the logarithms of retention factors (k) of MMA and MCHMA enantiomers and 1/T. It was demonstrated that the enantioseparations of MMA and MCHMA on PM-b-CD chiral column were enthalpy-driven processes. The modeling results can correctly predict the retention order and provide an atomistic account of how chiral discrimination takes place. It is found that the most stable structure of (R)-MMA/PM-b-CD complex is different with that of (S)-MMA/PM-b-CD complex. The main driving forces responsible for chiral recognition are hydrophobic forces and weak hydrogen bondings.

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Enantioseparation of 1-(p-bromophenyl)ethanol by crystallization of host–guest complexes with permethylated β-cyclodextrin: crystal structures and mechanisms of chiral recognition

Cited by 26 publications

References 34 publications

Application of preferential crystallization to resolve racemic compounds in a hybrid process

Application of preferential crystallization to resolve racemic compounds in a hybrid process

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

Experimental and Theoretical Studies on the Enantioseparation and Chiral Recognition of Mandelate and Cyclohexylmandelate on Permethylated β-Cyclodextrin Chiral Stationary Phase

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