Matches in SemOpenAlex for { <https://semopenalex.org/work/W2078482591> ?p ?o ?g. }
Showing items 1 to 64 of
64
with 100 items per page.
- W2078482591 endingPage "78" @default.
- W2078482591 startingPage "74" @default.
- W2078482591 abstract "A racemic sample of thiamylal, 5-allyl-5-(1-methylbutyl)-2-thiobarbituric acid, 1, has been shown to exhibit significant enantiomeric shift differences, ΔΔδ, for the CH 3 - CH proton absorptions when treated with the chiral lanthanide shift reagent, tris[3-(trifluoromethylhydroxy-methylene)- d-camphorato| europium (III), 2, in CDC1 3 at 28°. For example, at the relatively low molar ratio of 2:1 of 0.181, a value of ΔΔδ of 22 Hz (0.36δ) was observed, which increased to 26 Hz (0.43δ) at a molar ratio of 0.226. These large values, with relatively little lanthanide-induced line-broadening, should make possible the facile determination of optical purity of 1 even with a 60 MHz nmr spectrometer. Parallel studies were run using the achiral shift reagent, tris-(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) europium (III), 3, to confirm peak assignments. The considerable values of ΔΔδ may reflect the “soft base” character of the sulfur atom in 1. Less effective binding by sulfur to the lanthanide atom could lead to coordination by europium on the carbonyl oxygen, relatively close to the chiral center, providing enhanced AA5 values compared to some related compounds. While several other proton absorptions of 1 appear to show some observable ΔΔδ, they are less valuable for optical purity evaluation because of lower intensity, greater multiplicity, or small ΔΔδ value. The relative slopes of the plots of chemical shift, δ, for runs with 2 or 3, are consistent with the full assignment of the proton absorptions of 1 based on expected proximity of the protons to the complexed europium atom. The observed coupling constants of the vinyl hydrogens of 1 further support the assignments." @default.
- W2078482591 created "2016-06-24" @default.
- W2078482591 creator A5065791184 @default.
- W2078482591 creator A5090175520 @default.
- W2078482591 date "1984-01-01" @default.
- W2078482591 modified "2023-09-23" @default.
- W2078482591 title "Optical Purity Determination and 1H NMR Spectral Simplification with Lanthanide Shift Reagents. II. Thiamylal, 5-Allyl-5-(1-methylbutyl)-2-thiobarbituric Acid" @default.
- W2078482591 cites W1043389017 @default.
- W2078482591 cites W1990202310 @default.
- W2078482591 cites W2027538847 @default.
- W2078482591 cites W2042257994 @default.
- W2078482591 cites W2078949430 @default.
- W2078482591 cites W2488034612 @default.
- W2078482591 cites W2950535011 @default.
- W2078482591 cites W2952591789 @default.
- W2078482591 cites W2952978434 @default.
- W2078482591 cites W3005372042 @default.
- W2078482591 doi "https://doi.org/10.1366/0003702844554413" @default.
- W2078482591 hasPublicationYear "1984" @default.
- W2078482591 type Work @default.
- W2078482591 sameAs 2078482591 @default.
- W2078482591 citedByCount "11" @default.
- W2078482591 crossrefType "journal-article" @default.
- W2078482591 hasAuthorship W2078482591A5065791184 @default.
- W2078482591 hasAuthorship W2078482591A5090175520 @default.
- W2078482591 hasConcept C113196181 @default.
- W2078482591 hasConcept C145148216 @default.
- W2078482591 hasConcept C147789679 @default.
- W2078482591 hasConcept C178790620 @default.
- W2078482591 hasConcept C185592680 @default.
- W2078482591 hasConcept C201770740 @default.
- W2078482591 hasConcept C2777454769 @default.
- W2078482591 hasConcept C40875361 @default.
- W2078482591 hasConcept C502696234 @default.
- W2078482591 hasConceptScore W2078482591C113196181 @default.
- W2078482591 hasConceptScore W2078482591C145148216 @default.
- W2078482591 hasConceptScore W2078482591C147789679 @default.
- W2078482591 hasConceptScore W2078482591C178790620 @default.
- W2078482591 hasConceptScore W2078482591C185592680 @default.
- W2078482591 hasConceptScore W2078482591C201770740 @default.
- W2078482591 hasConceptScore W2078482591C2777454769 @default.
- W2078482591 hasConceptScore W2078482591C40875361 @default.
- W2078482591 hasConceptScore W2078482591C502696234 @default.
- W2078482591 hasIssue "1" @default.
- W2078482591 hasLocation W20784825911 @default.
- W2078482591 hasOpenAccess W2078482591 @default.
- W2078482591 hasPrimaryLocation W20784825911 @default.
- W2078482591 hasRelatedWork W1970047510 @default.
- W2078482591 hasRelatedWork W1970906235 @default.
- W2078482591 hasRelatedWork W1973472678 @default.
- W2078482591 hasRelatedWork W1996125188 @default.
- W2078482591 hasRelatedWork W1998075101 @default.
- W2078482591 hasRelatedWork W2019677843 @default.
- W2078482591 hasRelatedWork W2052693163 @default.
- W2078482591 hasRelatedWork W2082602202 @default.
- W2078482591 hasRelatedWork W2083392481 @default.
- W2078482591 hasRelatedWork W2117348797 @default.
- W2078482591 hasVolume "38" @default.
- W2078482591 isParatext "false" @default.
- W2078482591 isRetracted "false" @default.
- W2078482591 magId "2078482591" @default.
- W2078482591 workType "article" @default.