Nuclear magnetic resonance studies for the chiral recognition of (+)-(R)-18-crown-6-tetracarboxylic acid to amino compounds

Machida, Yoshio; Kagawa, Miyuki; Nishi, Hiroyuki

doi:10.1016/s0731-7085(02)00537-x

Cited by 59 publications

(36 citation statements)

References 31 publications

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“…The methine resonance of sixteen a-amino acids in D 2 O show a consistent trend that correlates with absolute configuration. 173 Lanthanide complexes. Organic-and water-soluble lanthanide complexes can be used in chloroform-d to analyze aamino acids.…”

Section: Nitrogen-and Oxygen-containing Compoundsmentioning

confidence: 99%

Assignment of absolute configuration using chiral reagents and NMR spectroscopy

2010

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Section: Nitrogen-and Oxygen-containing Compoundsmentioning

confidence: 99%

Assignment of absolute configuration using chiral reagents and NMR spectroscopy

2010

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“…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. [30][31][32][33][34][35][36][37][38] Calixarenes and calix [4]resorcinarenes are two other important families of cavity compounds, [39][40][41][42] although these have found limited application in NMR spectro-scopy.…”

Section: Introductionmentioning

confidence: 99%

“…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. [30][31][32][33][34][35][36][37][38] Calixarenes and calix [4]resorcinarenes are two other important families of cavity compounds, [39][40][41][42] although these have found limited application in NMR spectro-scopy. 1,[43][44][45][46][47][48][49][50][51] One exception is a tetrasulfonated calix [4] resorcinarene that contains optically pure L-prolinylmethyl groups (1).…”

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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“…The enantiomeric discrimination in the NMR spectra of primary amines with 1 is generally larger than that with other chiral crown ethers. [11][12][13][14][15] Furthermore, 1 is the only commercially available chiral crown ether for use as a chiral NMR solvating agent.…”

Section: Introductionmentioning

confidence: 99%

Chiral NMR discrimination of amines: Analysis of secondary, tertiary, and prochiral amines using (18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid

Lovely

Wenzel

2007

Chirality

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Enantiomeric discrimination is observed in the 1H and 13C NMR spectra of secondary and tertiary amines in the presence of (-)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (1). Nonequivalence of the resonances of prochiral nuclei in primary and secondary amines is also observed when they associate with 1. The amines are added in their neutral form and are protonated by the carboxylic acid groups of 1 to produce the corresponding ammonium and carboxylate ions. Secondary amines associate with 1 through two hydrogen bonds and an ion pair interaction. Tertiary amines can only form one hydrogen bond to accompany the ion pairing. Chiral discrimination in the 1H and 13C NMR spectra of a series of aryl-containing secondary amines is of sufficient magnitude to determine enantiomeric purities. The discrimination in the spectra of tertiary amines with 1 is smaller, but 13C NMR spectra provided enough distinction for the determination of enantiomeric purity.

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Nuclear magnetic resonance studies for the chiral recognition of (+)-(R)-18-crown-6-tetracarboxylic acid to amino compounds

Cited by 59 publications

References 31 publications

Assignment of absolute configuration using chiral reagents and NMR spectroscopy

Assignment of absolute configuration using chiral reagents and NMR spectroscopy

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

Chiral NMR discrimination of amines: Analysis of secondary, tertiary, and prochiral amines using (18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid

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