Vergleichende Untersuchung von Reaktivitäten und Ionenstrukturen beim monomolekularen Abbau isomerer Hydroxyzimtsäuremethylester unter Elektronenbeschuss

Kuster, Thomas; Mändli, H.; Robbiani, Richard; Seibl, J.

doi:10.1002/hlca.19780610311

Cited by 8 publications

(1 citation statement)

References 6 publications

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“…Compound 28 (the methyl ester of 26 ) shows that the carbonyl of the methyl ester is also efficient at effecting chlorine loss in the 2-position. However, compound 28 did not evidence direct loss of the methyl ester (seen as loss of methanol as was observed with o -hydroxy cinnamic acid methylesters [21]. These data further support the hypothesis that the loss of halogens, and chlorine in particular, occurs through a concerted mechanism.…”

Section: Resultssupporting

confidence: 63%

Substituted 3‐phenylpropenoates and related analogs: electron ionization mass spectral fragmentation and density functional theory calculations

Wheelock¹,

Colvin²,

Sanborn³

et al. 2008

J. Mass Spectrom.

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Analysis of ethyl 3-(2-chlorophenyl)-propenoate by electron ionization mass spectrometry showed the distinct loss of an ortho chlorine. To characterize the structural requisites for the observed mass fragmentation, a series of 30 halogen-substituted 3-phenylpropenoate-related structures were examined. All ester-containing alkene derivatives exhibited loss of the distinctive chlorine from the 2-position of the phenyl ring. Analogous derivatives with the halogen (chlorine or bromine) in the para position did not evidence selective halogen loss. Results demonstrated that substituted 3-phenylpropenoates and their analogs fragment via the formation of a previously reported benzopyrylium intermediate. To understand the correlation between the intramolecular radical substitution and the abundance and selectivity of the chlorine (or other halogen) displacement, density functional theory calculations were performed to determine the charge on the principal cation involved in the chlorine loss (in the ortho, meta and para positions), the charge for the neutral radical (non-cation), the excess alpha electron density on the relevant atom and the energy to form the cation from the neutral atom (ionization energy). Results showed that the selectivity and extent of halogen displacement correlated highly to the electrophilicity of the radical cation as well as the neutral radical. These data further support the proposed fragmentation mechanism involving intramolecular radical elimination.

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Section: Resultssupporting

confidence: 63%

Substituted 3‐phenylpropenoates and related analogs: electron ionization mass spectral fragmentation and density functional theory calculations

Wheelock¹,

Colvin²,

Sanborn³

et al. 2008

J. Mass Spectrom.

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ChemInform Abstract: COMPARATIVE STUDY OF REACTIVITIES AND ION STRUCTURES DURING THE ELECTRON IMPACT‐INDUCED MONOMOLECULAR DEGRADATION OF ISOMERIC HYDROXYCINNAMIC ACID METHYL ESTERS

Kuster¹,

Maendli²,

Robbiani³

et al. 1978

Chemischer Informationsdienst

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The fragmentations of substituted cinnamic acids after electron impact

Schaldach

Grützmacher

1980

Org. Mass Spectrom.

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The fragmentations of a number of cinnamic acids substituted at the phenyl ring have been studied with the aid of 70eV mass spectra and mass analysed ion kinetic energy spectra. Evidence is presented that the formation of [GH,O,]+ ions occurs by intramolecular aromatic substitution reactions. A mechanism is proposed for the energetically favourable loss of the substituents from meta and para positions of the phenyl ring. The analytical use of intramolecular aromatic substitution reactions is briefly discussed.

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Vergleichende Untersuchung von Reaktivitäten und Ionenstrukturen beim monomolekularen Abbau isomerer Hydroxyzimtsäuremethylester unter Elektronenbeschuss

Cited by 8 publications

References 6 publications

Substituted 3‐phenylpropenoates and related analogs: electron ionization mass spectral fragmentation and density functional theory calculations

Substituted 3‐phenylpropenoates and related analogs: electron ionization mass spectral fragmentation and density functional theory calculations

ChemInform Abstract: COMPARATIVE STUDY OF REACTIVITIES AND ION STRUCTURES DURING THE ELECTRON IMPACT‐INDUCED MONOMOLECULAR DEGRADATION OF ISOMERIC HYDROXYCINNAMIC ACID METHYL ESTERS

The fragmentations of substituted cinnamic acids after electron impact

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