Tris[3-(trifluoromethylhydroxymethylene)-d-camphorato]europium(III). Chiral shift reagent for direct determination of enantiomeric compositions

1971 ◽  
Vol 93 (22) ◽  
pp. 5913-5914 ◽  
Author(s):  
Harlan L. Goering ◽  
Jon N. Eikenberry ◽  
Gerald S. Koermer
Keyword(s):  
Direct Determination ◽  
Shift Reagent ◽  
Chiral Shift Reagent

scholarly journals Direct determination of enantiomeric enrichment of chiral, underivatized aminophosphonic acids — useful for enantioselective bioconversion results evaluation

2013 ◽  
Vol 11 (9) ◽  
pp. 1542-1547
Author(s):  
Kinga Kozyra ◽  
Magdalena Klimek-Ochab ◽  
Małgorzata Brzezińska-Rodak ◽  
Ewa Żymańczyk-Duda
Keyword(s):  
31P Nmr ◽  
Enantiomeric Excess ◽  
Direct Determination ◽  
Shift Reagent ◽  
Racemic Mixture ◽  
31P Nmr Spectroscopy ◽  
Phosphonic Acids ◽  
Aminophosphonic Acids ◽  
Chiral Solvating Agent

AbstractAbstract The possibility of applying 31P NMR spectroscopy for the determination of the enantiomeric excess of the racemic mixture of non-derivatized aminophosphonic acids with small side chains has been investigated. It is proven, that the effectiveness of the application of a chiral solvating agent strongly depends on the concentration of applied shift reagent and on the pH of the particular experiment. Effectual resolution protocols are elaborated for following phosphonic acids: 1-aminoethanephosphonic acid, 1-amino-2-methylpropanephosphonic acid, 1-aminophenylmethanephosphonic acid, 1-aminophenylmethane-phosphonic acid and 1-amino-2-phenylethanephosphonic acid. Graphical abstract

Improved Method for Optical Purity Determination of Ketazolam with Chiral Shift Reagent

1990 ◽  
Vol 23 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Laurine A. Laplanche ◽  
Robert Rothchild
Keyword(s):  
Optical Purity ◽  
Shift Reagent ◽  
Improved Method ◽  
Purity Determination ◽  
Chiral Shift Reagent

A new chiral shift reagent for the determination of enantiomeric excess and absolute configuration in cyanohydrins

2009 ◽  
pp. 1067 ◽  
Author(s):  
Lomary S. Moon ◽  
Ravinder S. Jolly ◽  
Yoganjaneyulu Kasetti ◽  
Prasad V. Bharatam
Keyword(s):  
Absolute Configuration ◽  
Enantiomeric Excess ◽  
Shift Reagent ◽  
Chiral Shift Reagent

Determination of the enantiomeric purity of disubstituted β-lactams by NMR spectroscopy using a chiral shift reagent

1990 ◽  
Vol 28 (7) ◽  
pp. 606-611 ◽  
Author(s):  
J. Belleney ◽  
C. Bui ◽  
F. J. Carriere
Keyword(s):  
Nmr Spectroscopy ◽  
Shift Reagent ◽  
Enantiomeric Purity ◽  
Chiral Shift Reagent

NMR Studies of Drugs. Application of a Chiral Lanthanide Shift Reagent for Potential Direct Determination of Enantiomeric Excess of Methsuximide

1991 ◽  
Vol 24 (10) ◽  
pp. 1373-1394 ◽  
Author(s):  
Robert J. Reifsneider ◽  
Bernard H. Hoffman ◽  
Kunisi S. Venkatasubban ◽  
Robert Rothchild ◽  
Rolf Martin
Keyword(s):  
Enantiomeric Excess ◽  
Direct Determination ◽  
Shift Reagent ◽  
Lanthanide Shift Reagent ◽  
Nmr Studies

ChemInform Abstract: A New Chiral Shift Reagent for the Determination of Enantiomeric Excess and Absolute Configuration in Cyanohydrins.

ChemInform ◽  
2009 ◽  
Vol 40 (22) ◽  
Author(s):  
Lomary S. Moon ◽  
Ravinder S. Jolly ◽  
Yoganjaneyulu Kasetti ◽  
Prasad V. Bharatam
Keyword(s):  
Absolute Configuration ◽  
Enantiomeric Excess ◽  
Shift Reagent ◽  
Chiral Shift Reagent

Lanthanide Induced Enhancement of Enantiomeric Shifts in Chiral Solvents and its Use in the Determination of Optical Purity

1973 ◽  
Vol 51 (22) ◽  
pp. 3726-3732 ◽  
Author(s):  
C. P. R. Jennison ◽  
Donald Mackay
Keyword(s):  
Chemical Shift ◽  
Fractional Crystallization ◽  
Sulfonic Acid ◽  
Optical Purity ◽  
Shift Reagent ◽  
Lanthanide Shift Reagent ◽  
Chemical Shift Difference ◽  
Chiral Shift Reagent ◽  
Simple Molecules

The chemical shift difference (Δv) between corresponding groups in enantiomers in the presence of both a chiral solvent ((−)-2,2,2-trifluorophenylethanol or (+)-1-phenylethylamine) and an achiral lanthanide shift reagent (Eu(dpm)3 or Eu(fod)3) is much greater than in the chiral solvent alone. In general, for simple molecules having one coordination site the Δv was smaller than that obtained with the chiral shift reagent Eu(HFC)3. Comparable values of Δv, however, were obtained with the 1,3,4-oxadiazine derivatives 4a and b, and 5, suggesting that the "chiral solvate shift system" is best suited to differentiating more complex enantiomers having several coordination sites.The shift system was used to determine the optical purity of two partially resolved substances. One of these was the (+)-oxadiazine 4a, produced in the asymmetric isomerization of the bridged pyridazine 3a by (+)-camphor-10-sulfonic acid, and optically enriched by only one fractional crystallization. The enantiomeric enrichment in the isomerization was 4.21 ± 0.08%.

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