Effects of Medium and Substituents on Dissociationof 4,4'-Disubstituted Bis(benzenesulfon)imides

Ludwig, Miroslav; Štverka, Pavel

doi:10.1135/cccc19961205

Cited by 6 publications

(2 citation statements)

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“…The acidity data in DMF was critically evaluated, analogously to DMSO. The data from works [43,[49][50][51][52][53][54][55][56][57] was found consistent, or the need for correction could not be identified.…”

Section: Creating and Validating The Predictive Equationsmentioning

confidence: 99%

Strengths of Acids in Acetonitrile

et al. 2021

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The equilibrium acidity scale (pKa scale) in acetonitrile has been supplemented by numerous new compounds and new ΔpKa measurements. It now contains altogether 231 acids – over twice more than published previously – linked by 569 ΔpKa measurements and spans between the pKa values of hydrogen iodide (2.8) and indole (32.57), covering close to 30 orders of magnitude. Measurement results acquired over the last 15 years were added to the scale and new least‐squares treatment was carried out. The treatment yielded revised pKa values for the compounds published previously, with the root mean square difference between revised and previous values 0.04, demonstrating very good stability of the scale. Correlation equations were developed for estimating pKa values for the studied types of compounds in water, DMSO, DMF, and 1,2‐dichloroethane on the basis of pKa values in acetonitrile. These equations enable predicting pKa values with an average error around or less than 1 pKa unit, which is a sufficient accuracy for many applications. The scale is expected to be a useful tool for the widest possible research areas in organic chemistry, electrochemical power sources, catalysis, etc.

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Section: Creating and Validating The Predictive Equationsmentioning

confidence: 99%

Strengths of Acids in Acetonitrile

et al. 2021

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“…In DCE, generally poor agreement was observed, with amines significantly underpredicted compared to carboxylic acids. The pK a values for the carboxylic acids and picric acid come from the same collection of papers 50,51,53,63,64 (except for acetic acid at pH = 29.2, the outlier on the right of Figure 6), and are anchored to the pK a of hydriodic acid = 7.9 (corresponding to pK a of picric acid = 13.7). The pK a values for the three bases are also anchored to the same value.…”

Section: Experimental Data For Dcementioning

confidence: 99%

pKa Prediction in Non-Aqueous Solvents

Zheng,

Al Ibrahim,

Green

2024

Preprint

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Acid dissociation constants (pKa) are widely measured and studied, most typically in water. Comparatively few datasets and models for non-aqueous pKa values exist. In this work, we demonstrate how the pKa in one solvent can be accurately determined using reference data in another solvent, corrected by solvation energy calculations from the COSMO-RS method. We benchmark this approach in ten different solvents, and find that pKa values calculated in six solvents deviate from experimental data on average by less than 1 pH unit. We observe comparable performance on a more diverse test set including amino acids and drug molecules, with higher error for large molecules. The model performance in four other solvents is worse, with some MAEs exceeding 3 pH units; we discuss how such errors arise due to both model error and inconsistency in data calibration. Finally, we demonstrate how this technique can be used to estimate the proton transfer energy between different solvents, and use this to report a value of the proton’s solvation energy in formamide, a quantity that has does not have a consensus value in literature.

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1,3‐O‐Transposition or Trisubstituted Z‐Enol Ester? A Comparative Study of Reactions of Ynones

Sun

Chen

Zhang

et al. 2019

Chemistry An Asian Journal

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Ynones are useful substrates for transitionmetal-mediated synthesis. The Au I -catalyzed 1,3-O-transposition is an important reactiono fy nones. Recently,a n efficient Cu I -catalyzed synthesis of trisubstituted Z-enol esters via interrupting the traditional 1,3-O-transposition reaction of ynones was reportedb yZ hu's group. Herein, density functional theory studies disclosed that the hydrogen bond formed by carboxylic acid plays an important role for the reactivitya nd selectivityi nt his novel reaction. Aq ualitative rule was also found to explain the substituent effect in the ynone substrate, and this is consistent with experiments. The Au I -catalyst and Cu I -catalyst were further compared to interpret the essential cause of why the Au I -catalyst prefers the 1,3-O-transpostion reaction. These conclusions might be helpful for the rational design of reactions of ynones.Scheme1.1,3-O-transpostionofy nonebyA u I catalyst and trisubstituted Zenol ester formationo fy none by Cu I catalyst.[a] Dr.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

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Effects of Medium and Substituents on Dissociationof 4,4'-Disubstituted Bis(benzenesulfon)imides

Cited by 6 publications

References 0 publications

Strengths of Acids in Acetonitrile

Strengths of Acids in Acetonitrile

pKa Prediction in Non-Aqueous Solvents

1,3‐O‐Transposition or Trisubstituted Z‐Enol Ester? A Comparative Study of Reactions of Ynones

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