Matches in SemOpenAlex for { <https://semopenalex.org/work/W2067484093> ?p ?o ?g. }
- W2067484093 endingPage "226" @default.
- W2067484093 startingPage "220" @default.
- W2067484093 abstract "The effects of substitution and solvent on the configurational equilibria of neutral and protonated N-(4-Y-substituted-phenyl) peracetylated 5-thioglucopyranosylamines (Y = OMe, H, CF3, NO2) 1−4 and N-(4-Y-substituted-phenyl) peracetylated glucopyranosylamines (Y = OMe, H, NO2) 9−11 are described. The configurational equilibria were determined by direct integration of the resonances of the individual isomers in the 1H NMR spectra after equilibration of both α- and β-isomers. The equilibrations of the neutral compounds 1−4 in CD3OD, CD3NO2, and (CD3)2CO were achieved by HgCl2 catalysis and those of the neutral compounds 9−11 in CD2Cl2 and CD3OD by triflic acid catalysis. The equilibrations of the protonated compounds in both the sulfur series (solvents, CD3OD, CD3NO2, (CD3)2CO, CDCl3, and CD2Cl2) and oxygen series (solvents, CD2Cl2 and CD3OD) were achieved with triflic acid. The substituent and solvent effects on the equilibria are discussed in terms of steric and electrostatic effects and orbital interactions associated with the endo-anomeric effect. A generalized reverse anomeric effect does not exist in neutral or protonated N-aryl-5-thioglucopyranosylamines and N-arylglucopyranosylamines. The anomeric effect ranges from 0.85 kcal mol-1 in 2 to 1.54 kcal mol-1 in 10. The compounds 1−4 and 9−11 show an enhanced endo-anomeric effect upon protonation, ranging from 1.73 kcal mol-1 in 2 to 2.57 kcal mol-1 in 10. We estimate the increase in the anomeric effect upon protonation of 10 to be approximately 1.0 kcal mol-1. However, this effect is offset by steric effects due to the associated counterion which we estimate to be approximately 1.2 kcal mol-1. The values of Keq(axial−equatorial) in protonated 1−4 increase in the order OMe < H < CF3 < NO2, in agreement with the dominance of steric effects (due to the counterion) over the endo-anomeric effect. The values of Keq(axial−equatorial) in protonated 9−11 show the trend OMe > H < NO2 that is explained by the balance of the endo-anomeric effect and steric effects in the individual compounds. The trends in the values of the C1−H1 coupling constants for 1−4 and the corresponding deacetylated compounds 5−8 as a function of substituent and α- or β-configuration are discussed in terms of the Perlin effect and the interplay of the endo- and exo-anomeric effects." @default.
- W2067484093 created "2016-06-24" @default.
- W2067484093 creator A5000071144 @default.
- W2067484093 creator A5010731955 @default.
- W2067484093 creator A5032914936 @default.
- W2067484093 creator A5064677011 @default.
- W2067484093 date "1999-12-17" @default.
- W2067484093 modified "2023-09-26" @default.
- W2067484093 title "Is There a Generalized Reverse Anomeric Effect? Substituent and Solvent Effects on the Configurational Equilibria of Neutral and Protonated <i>N</i>-Arylglucopyranosylamines and <i>N</i>-Aryl-5-thioglucopyranosylamines" @default.
- W2067484093 cites W1965343029 @default.
- W2067484093 cites W1977848164 @default.
- W2067484093 cites W1985492283 @default.
- W2067484093 cites W1985630987 @default.
- W2067484093 cites W1988249312 @default.
- W2067484093 cites W1993392513 @default.
- W2067484093 cites W1994375700 @default.
- W2067484093 cites W2002439906 @default.
- W2067484093 cites W2015735281 @default.
- W2067484093 cites W2021768535 @default.
- W2067484093 cites W2034426506 @default.
- W2067484093 cites W2034848039 @default.
- W2067484093 cites W2035645668 @default.
- W2067484093 cites W2042352973 @default.
- W2067484093 cites W2045412891 @default.
- W2067484093 cites W2050937290 @default.
- W2067484093 cites W2058534171 @default.
- W2067484093 cites W2064556551 @default.
- W2067484093 cites W2071583099 @default.
- W2067484093 cites W2073647353 @default.
- W2067484093 cites W2079109112 @default.
- W2067484093 cites W2079616092 @default.
- W2067484093 cites W2080118797 @default.
- W2067484093 cites W2082830329 @default.
- W2067484093 cites W2084377377 @default.
- W2067484093 cites W2084808439 @default.
- W2067484093 cites W2102862096 @default.
- W2067484093 cites W2128903166 @default.
- W2067484093 cites W2130432176 @default.
- W2067484093 cites W2132768429 @default.
- W2067484093 cites W2146077325 @default.
- W2067484093 cites W2172169578 @default.
- W2067484093 cites W3005415200 @default.
- W2067484093 doi "https://doi.org/10.1021/jo991520j" @default.
- W2067484093 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/10813919" @default.
- W2067484093 hasPublicationYear "1999" @default.
- W2067484093 type Work @default.
- W2067484093 sameAs 2067484093 @default.
- W2067484093 citedByCount "38" @default.
- W2067484093 countsByYear W20674840932012 @default.
- W2067484093 countsByYear W20674840932013 @default.
- W2067484093 countsByYear W20674840932015 @default.
- W2067484093 countsByYear W20674840932016 @default.
- W2067484093 countsByYear W20674840932017 @default.
- W2067484093 countsByYear W20674840932020 @default.
- W2067484093 countsByYear W20674840932021 @default.
- W2067484093 countsByYear W20674840932022 @default.
- W2067484093 countsByYear W20674840932023 @default.
- W2067484093 crossrefType "journal-article" @default.
- W2067484093 hasAuthorship W2067484093A5000071144 @default.
- W2067484093 hasAuthorship W2067484093A5010731955 @default.
- W2067484093 hasAuthorship W2067484093A5032914936 @default.
- W2067484093 hasAuthorship W2067484093A5064677011 @default.
- W2067484093 hasConcept C132439834 @default.
- W2067484093 hasConcept C14158195 @default.
- W2067484093 hasConcept C145148216 @default.
- W2067484093 hasConcept C147597530 @default.
- W2067484093 hasConcept C155647269 @default.
- W2067484093 hasConcept C161790260 @default.
- W2067484093 hasConcept C178790620 @default.
- W2067484093 hasConcept C185592680 @default.
- W2067484093 hasConcept C191423414 @default.
- W2067484093 hasConcept C201194858 @default.
- W2067484093 hasConcept C2778689049 @default.
- W2067484093 hasConcept C2779128551 @default.
- W2067484093 hasConcept C2780263894 @default.
- W2067484093 hasConcept C2780471494 @default.
- W2067484093 hasConcept C2781076698 @default.
- W2067484093 hasConcept C30095370 @default.
- W2067484093 hasConcept C32909587 @default.
- W2067484093 hasConcept C71240020 @default.
- W2067484093 hasConcept C7947691 @default.
- W2067484093 hasConceptScore W2067484093C132439834 @default.
- W2067484093 hasConceptScore W2067484093C14158195 @default.
- W2067484093 hasConceptScore W2067484093C145148216 @default.
- W2067484093 hasConceptScore W2067484093C147597530 @default.
- W2067484093 hasConceptScore W2067484093C155647269 @default.
- W2067484093 hasConceptScore W2067484093C161790260 @default.
- W2067484093 hasConceptScore W2067484093C178790620 @default.
- W2067484093 hasConceptScore W2067484093C185592680 @default.
- W2067484093 hasConceptScore W2067484093C191423414 @default.
- W2067484093 hasConceptScore W2067484093C201194858 @default.
- W2067484093 hasConceptScore W2067484093C2778689049 @default.
- W2067484093 hasConceptScore W2067484093C2779128551 @default.
- W2067484093 hasConceptScore W2067484093C2780263894 @default.
- W2067484093 hasConceptScore W2067484093C2780471494 @default.
- W2067484093 hasConceptScore W2067484093C2781076698 @default.
- W2067484093 hasConceptScore W2067484093C30095370 @default.
- W2067484093 hasConceptScore W2067484093C32909587 @default.