Carbon‐13 NMR spectra of some 2‐ ethylthio‐4′‐substituted acetophenones and their mono‐ and di‐oxygenated derivatives

Olivato, Paulo R.; Bonfada, Élida; Rittner, Roberto

doi:10.1002/mrc.1260300116

Cited by 23 publications

(17 citation statements)

References 11 publications

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“…For Ia − h and IIa − d the 13 C chemical shift of the carbonyl carbon is only influenced by inductive effects from the α substituents (which are modulated by the remote substituent in the ring). In this case there is an upfield shift relative to the acetophenone value (197.92 ppm), Table , which is consistent with the phenoxy and anilino groups being electronegative. , The 13 C chemical shifts of the carbonyl carbons in similarly substituted α-phenoxy- and α-phenylaminoacetophenones correlate linearly with each other with a slope of 0.892, Figure . The slope, which is less than unity, is consistent with the oxygen atom being less polarizable than the NH group.…”

Section: Resultssupporting

confidence: 62%

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹

1996

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The formal reduction potential (E°) of α-phenoxyacetophenone has been determined from the voltammetric peak potential obtained by linear sweep voltammetry in combination with the rate constant for fragmentation of the radical anion which had been determined by laser flash photolysis. The E° values of a number of α-aryloxyacetophenones were then estimated from a correlation of the 13C chemical shifts of the carbonyl carbon and a similar correlation (E° versus 13C chemical shift) within a series of substituted α-anilinoacetophenones. Using these potentials (which vary by only 34 mV over a wide range of substituents) the rate constants for fragmentation of the α-aryloxyacetophenone radical anions were determined from digital simulation of the corresponding voltammetric waves. The fragmentation rate constants were shown to correlate with the pK a of the corresponding phenols. However, the kinetic range was too small and the experimental errors too large to allow a distinction between a linear and quadratic free energy dependence. A thermochemical analogy between the leaving group ability in reactions of radical anions and that in simple heterolysis of closed shell compounds is developed. The utility of these compounds as potential electron transfer probes is discussed.

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Section: Resultssupporting

confidence: 62%

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹

1996

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“…A THF solution of 2-(ethylsulfinyl)-(4'-substituted)-acetophenone, prepared as previously described [15], was added to a solution of LDA in THF at 195 K. After 20 min, a solution of phenylselanyl bromide in THF was added dropwise to the enolate solution.…”

Section: Methodsmentioning

confidence: 99%

Stereochemical and electronic interaction studies of 4′-substituted 2-(phenylselanyl)-2-(ethylsulfinyl)-acetophenones

Cerqueira¹,

Olivato

Rodrigues

et al. 2017

Journal of Molecular Structure

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Infrared carbonyl band analysis, supported by B3LYP/6-31+G(d,p) and single-point PCM calculations, natural bond orbital (NBO) analysis and X-ray diffraction were carried out for the diastereoisomers of a selection of 4'-substituted 2-(phenylselanyl)-2-(ethylsulfinyl)-acetophenones bearing the substituents NO2 1a, Br 2a, H 3a, Me 4a and OMe 5a for the CRSR/CSSS enantiomeric pair and Br 2b and Me 4b for the CRSS/CSSR pair. For the gas phase, the theoretical data indicated the existence of three stable conformations for the CRSR series and only two for the CRSS series. For the whole CRSR series 1a-5a, the most stable c1 and the intermediate c2 conformers have similar νCO frequencies, lowered by about 20 cm -1 with respect to the less stable c3. Likewise, the less stable c2 conformers for the CRSS series 2b and 4b exhibit the higher νCO frequencies. The single-point PCM calculations show that the relative abundance of both the less stable c3 CRSR and c2 CRSS conformers, in the gas phase, progressively increases as the dielectric constant of the media increases. The balance between the electrostatic and orbital interactions controls the calculated stability for compounds 1a-5a (CRSR/ CSSS), along with the νCO frequency order of the three conformers.Conversely, the larger stabilisation of the c1 conformer with respect to the c2 one in the

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“…For related structures, see: Zukerman-Schpector et al (1999, 2006. For related literature, see: Distefano et al (1991); Olivato et al (1992Olivato et al ( , 1997Olivato et al ( , 2003Olivato et al ( , 2004; Dal Colle et al (1995). For ring conformational analysis, see: Cremer & Pople (1975).…”

Section: Related Literaturementioning

confidence: 99%

1-Methyl-3-phenylsulfonyl-2-piperidone

et al. 2008

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The piperidone ring in the title compound, C12H15NO3S, has a slightly distorted half-chair conformation with the methyl, carbonyl and phenylsulfonyl ring substituents occupying equatorial, equatorial and axial positions, respectively. Molecules are connected into centrosymmetric dimers via C—H⋯O interactions and these associate into layers via C—H⋯O—S contacts. Further C—H⋯O interactions involving both the carbonyl and sulfonyl O atoms consolidate the crystal packing by providing connections between the layers.

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Carbon‐13 NMR spectra of some 2‐ ethylthio‐4′‐substituted acetophenones and their mono‐ and di‐oxygenated derivatives

Cited by 23 publications

References 11 publications

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹

Stereochemical and electronic interaction studies of 4′-substituted 2-(phenylselanyl)-2-(ethylsulfinyl)-acetophenones

1-Methyl-3-phenylsulfonyl-2-piperidone

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Carbon‐13 NMR spectra of some 2‐ ethylthio‐4′‐substituted acetophenones and their mono‐ and di‐oxygenated derivatives

Cited by 23 publications

References 11 publications

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones1

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones1

Stereochemical and electronic interaction studies of 4′-substituted 2-(phenylselanyl)-2-(ethylsulfinyl)-acetophenones

1-Methyl-3-phenylsulfonyl-2-piperidone

Contact Info

Product

Resources

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Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹

Electrochemistry of Electron-Transfer Probes. The Role of the Leaving Group in the Cleavage of Radical Anions of α-Aryloxyacetophenones¹