Cyclodextrins as chiral complexing agents in water, and their application to optical purity measurements

Greatbanks, D.; Pickford, R.

doi:10.1002/mrc.1260250306

Cited by 151 publications

(42 citation statements)

References 8 publications

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“…Deuterated NMR solvents were obtained from Aldrich Chemical and used as received. Europium(III) and praseodymium(III) complexes of 6,6,7,7,8,8,8heptaÑuorooctane-3,5-dione (fod),23 the silver complex of fod,24 Crown 116 and Crown 217 were prepared, puriÐed and characterized according to published procedures. All solvents used in the synthetic preparations were dried by established procedures prior to use.…”

Section: Reagentsmentioning

confidence: 99%

Lanthanide-Crown Ether Mixtures as Chiral NMR Shift Reagents for Amino Acid Esters, Amines and Amino Alcohols

1997

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Two chiral crown ethers, 2,3:4,5‐bis[1,2‐(3‐phenylnaphtho)‐1,6,9,12,15,18‐hexaoxacycloeicosa‐2,4‐diene and 1,2:5,6‐di‐O‐isopropylidene‐3,4‐[(tert‐butylbenzenediyl)bis(oxyethoxy)ethyl‐D‐mannitol, were evaluated as organic‐soluble chiral NMR resolving agents. The crown ethers are useful resolving agents for protonated amino acid esters, amines and amino alcohols. Enantiodiscrimination with the crown ethers is better in methanol than in acetonitrile or chloroform. Organic‐soluble lanthanide tetrakis(β‐diketonate) anions, which are formed in solution by mixing a lanthanide tris(β‐diketonate) and silver β‐diketonate, can be added to crown–substrate mixtures to enhance the enantiomeric resolution. The lanthanide‐induced enhancement occurs because the enantiomers of the substrate have different association constants with the crown ethers. The enantiomer that associates less favorably with the crown ether is more available to complex with the lanthanide. © 1997 by John Wiley & Sons, Ltd.

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Section: Reagentsmentioning

confidence: 99%

Lanthanide-Crown Ether Mixtures as Chiral NMR Shift Reagents for Amino Acid Esters, Amines and Amino Alcohols

1997

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“…The interior of the cavity is often hydrophobic, such that the hydrophobic portion of organic salts is stabilized by insertion into the cavity in water. Native cyclodextrins, [14][15][16][17][18] trimethyl-b-cyclodextrin, [19][20][21][22][23] and carboxymethylated cyclodextrins [24][25][26][27][28][29] are one family of water-soluble cavity compounds. The crown ether (18-crown-6)-2,3,11,12-tetracarboxylic acid has been used in water as a chiral solvating agent for primary amines, 30 although the enantiomeric discrimination with this crown ether is better in methanol and acetonitrile.…”

Section: Introductionmentioning

confidence: 99%

Water‐soluble calix[4]resorcinarenes as chiral NMR solvating agents for bicyclic aromatic compounds

2009

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Water-soluble calix[4]resorcinarenes with proline, 3-hydroxyproline, and 4-hydroxyproline substituent groups are evaluated as chiral NMR solvating agents on a series of bicyclic aromatic compounds with naphthyl, indole, dihydroindole, and indane rings. The substrates interact with the calixresorcinarene through insertion of the aromatic ring into the cavity. Most of the substrates are analyzed as cationic species, although one anionic species is analyzed. All of the substrates exhibit enantiomeric discrimination in the 1H-NMR spectrum with one or more of the calixresorcinarenes. In most cases, the hydroxyproline derivatives are more effective at causing enantiodifferentiation than the corresponding proline derivative. Presumably, the hydroxyl group on the proline moieties is involved in interactions with the substituent groups of the substrate that are important in creating chiral recognition. The enantiomeric discrimination in the 1H-NMR spectrum is large enough for many resonances to permit the analysis of enantiomeric purity.

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“…Greatbanks & Pickford (Greatbanks & Pickford, 1987) concluded that when  H3 >  H5, occurs partial inclusion of the guest inside the cavity and when  H3 <  H5, a total inclusion takes place.…”

Section: H-nuclear Magnetic Resonance Spectroscopymentioning

confidence: 99%

Review: Cyclodextrin Inclusion Complexes Probed by NMR Techniques

Pessine¹,

Calderini²,

Alexandrino³

2012

Magnetic Resonance Spectroscopy

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Cyclodextrins as chiral complexing agents in water, and their application to optical purity measurements

Cited by 151 publications

References 8 publications

Lanthanide-Crown Ether Mixtures as Chiral NMR Shift Reagents for Amino Acid Esters, Amines and Amino Alcohols

Lanthanide-Crown Ether Mixtures as Chiral NMR Shift Reagents for Amino Acid Esters, Amines and Amino Alcohols

Water‐soluble calix[4]resorcinarenes as chiral NMR solvating agents for bicyclic aromatic compounds

Review: Cyclodextrin Inclusion Complexes Probed by NMR Techniques

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