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Chemistry - A European Journal
Volumn 20, Issue 50, 2014, Pages 16680-16687
The ortho-substituent effect on the Ag-Catalysed decarboxylation of benzoic acids
Author keywords

Catalysis; Decarboxylation; Density functional calculations; Kinetics; Linear free energy relationships
Indexed keywords

ACTIVATION ENERGY; CARBOXYLATION; CATALYSIS; DENSITY FUNCTIONAL THEORY; ENZYME KINETICS; FREE ENERGY;
EID: 84922375095     PISSN: 09476539     EISSN: 15213765     Source Type: Journal    
DOI: 10.1002/chem.201402931     Document Type: Article
Times cited : (56)
References (61)
  • 28
    • 84922351237 scopus 로고    scopus 로고
    • A combined computational study was carried out by Gooen et al. (see ref. [12]) using an Ag/NMP catalyst system, which yielded a reduced activation barrier to decarboxylation with Ag compared to the Cu/1, 10- phenanthroline system
    • A combined computational study was carried out by Gooen et al. (see ref. [12]) using an Ag/NMP catalyst system, which yielded a reduced activation barrier to decarboxylation with Ag compared to the Cu/1, 10- phenanthroline system.
  • 29
    • 84958727271 scopus 로고    scopus 로고
    • Kozlowski et al. have recently reported a combined experimental and theoretical study on Pd-catalysed decarboxylation (see ref. [8b]), from which they concluded that the rate-determining step can be either the decarboxylation or the protodemetallation, depending on the substrate. The Pd-catalysed protodecarboxylation regularly requires an exogenous proton/hydride source for catalyst regeneration, whereas this is not required in the Ag-catalysed system. The aryl-Ag intermediate is very nucleophilic and readily undergoes protodemetallation, thus supporting the inference that the decarboxylation is the rate-determining step in the Ag-catalysed protodecarboxylation
    • Kozlowski et al. have recently reported a combined experimental and theoretical study on Pd-catalysed decarboxylation (see ref. [8b]), from which they concluded that the rate-determining step can be either the decarboxylation or the protodemetallation, depending on the substrate. The Pd-catalysed protodecarboxylation regularly requires an exogenous proton/hydride source for catalyst regeneration, whereas this is not required in the Ag-catalysed system. The aryl-Ag intermediate is very nucleophilic and readily undergoes protodemetallation, thus supporting the inference that the decarboxylation is the rate-determining step in the Ag-catalysed protodecarboxylation.
  • 33
    • 84958727272 scopus 로고    scopus 로고
    • The prominence of the ortho effect is also observed in the correlation between the DG ortho DG paradifference and the activation energy barrier DG ortho, with a significant correlation coefficient (r) of 0.86 (Figure S3). Moreover, a correlation of 0.93 is observed when comparing the ortho and meta isomers (Figure S4). Accordingly, there is also a positive correlation of 0.77 between the Cipso-CO2 bond length differences in the TS and CP3 structures and the activation energies for the ortho isomers (Figure S5). Therefore, compounds that require greater structural change between the CP3 and TS structures tend to be less susceptible to decarboxylation. This relationship infers that electron-withdrawing groups weaken the adjacent Cipso-CO2 bond by removing bonding electron density, indicating that the electronic influence is not limited to a stabilisation of the transition-state structure
    • The prominence of the ortho effect is also observed in the correlation between the DG ortho DG paradifference and the activation energy barrier DG ortho, with a significant correlation coefficient (r) of 0.86 (Figure S3). Moreover, a correlation of 0.93 is observed when comparing the ortho and meta isomers (Figure S4). Accordingly, there is also a positive correlation of 0.77 between the Cipso-CO2 bond length differences in the TS and CP3 structures and the activation energies for the ortho isomers (Figure S5). Therefore, compounds that require greater structural change between the CP3 and TS structures tend to be less susceptible to decarboxylation. This relationship infers that electron-withdrawing groups weaken the adjacent Cipso-CO2 bond by removing bonding electron density, indicating that the electronic influence is not limited to a stabilisation of the transition-state structure.
  • 49
    • 84922358083 scopus 로고    scopus 로고
    • It is assumed that groups such as OR orientate themselves in such a way as to minimise their size; thus, the van der Waals radius is only directly related to the size of the oxygen atom (see ref. [17])
    • It is assumed that groups such as OR orientate themselves in such a way as to minimise their size; thus, the van der Waals radius is only directly related to the size of the oxygen atom (see ref. [17]).
  • 54
    • 0004066445 scopus 로고    scopus 로고
    • Vrije Universiteit, Amsterdam, The Netherlands
    • SCM, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands, http://www.scm.com.
    • Theoretical Chemistry
  • 61
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    • R Foundation for Statistical Computing, Vienna, Austria
    • R Core Team (2013). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.R-project.org.
    • (2013) R: A Language and Environment for Statistical Computing

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.