Kinetik und mechanismus des zerfalls von monomethylthalliumdiacetat in Lösung

Pohl, Ursula; Huber, F.

doi:10.1016/s0022-328x(00)91789-3

Cited by 11 publications

(3 citation statements)

References 9 publications

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“…Cette rCaction est accClCrCe par les ions C1-(7). Ceci est expliquC en admettant que C1-agit comme rCactif nuclCop11ile dans I'attaque S,2 sur le carbone portant le thallium (8). Ce changement du mecanisme d'intervention des ions C1-montre l'importance de la participation ou la migration des groupes en position P (H, alkyle, aryle, OH, OR, OOCR) lors de la rupture du lien C-TI dans le cas des composCs d'oxythallation.…”

Section: Mkthodes Cinktiquesunclassified

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂

Nadon¹,

Zador²

1977

Can. J. Chem.

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Chem. 55, 3590 (1977). L'influence de la coordination du thallium sur la vitesse de decomposition du compose d'oxythallation C6H5-CH(OCH3)-CHZT1Xz(R'T1X2) a ete BtudiCe en milieu eau-methanol.En presence de faibles concentrations d'ions C1-, la vitesse de decomposition oxydante diminue a cause de la formation d'especes R'TIClf et -RfT1C1OH, ces deux dernieres etant moins reactives que l'espkce R'TlZ+. A haute concentration en ions C1-, il y a formation d'especes RfT1ClZ ou R'T1Cl3-; on observe alors la decomposition en reactifs de depart, soit le styrene et le Tl(III), similairement observee pour les organomercuriques.Le mecanisme des reactions est discute en termes de changement du caractere Clectrophile du thallium dO a la coordination par le ligand.LOUISE NADON and MIKLOS ZADOR. Can. J. Chem. 55,3590 (1977). The effect of coordination of thallium was studied on the rate of decomposition in methanolwater of the product of oxythallation, C6H5-CH(OCH3)-CHZTIXZ(R'TIXz). At low C1-ion concentrations, the rate of the oxidative decomposition decreased because of the formation of RfT1C1+ and R'TICIOH, both of which are less reactive than R'TlZ+. At high C1-ion concentration, R'TICI, or R'TlC1,-are formed and a decomposition to the starting materials, namely styrene and Tl(III), was observed; this is analogous to the behaviour of organomercurials. The mechanism of the reactions is discussed in terms of the electrophilic character of thallium effected by the coordination by ligand.[Journal translation]

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Section: Mkthodes Cinktiquesunclassified

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂

Nadon¹,

Zador²

1977

Can. J. Chem.

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“…Functionalization of Tl III –alkyl bonds also occurs in water solvent . For example, at ∼100 °C (OAc) 2 Tl III (CH 3 ) (OAc = acetate) dissolved in water results in two-electron reductive functionalization of the Tl III –C bond to give Tl I (OAc), methyl acetate (MeOAc), and methanol (MeOH, Scheme a) .…”

Section: Introductionmentioning

confidence: 99%

Mechanisms and Reactivity of Tl(III) Main-Group-Metal–Alkyl Functionalization in Water

Gustafson

Konnick²,

Periana

et al. 2018

Organometallics

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Metal-mediated C–H activation reactions generate metal–alkyl intermediates that can be converted into carbon–oxygen bonds through functionalization reactions. While the mechanisms and reactivity of C–H activation reactions have been well studied for transition-metal complexes, much less is known about functionalization reactions, especially for main-group-metal–alkyl complexes. Here we report density functional theory calculations on the reaction thermodynamics and kinetic pathways for main-group, p-block-metal TlIII–methyl functionalization reactions in water using a combination of continuum and explicit/continuum solvent models. Specifically, we examined the oxygen functionalization of (OAc)TlIII(CH3)2 and (OAc)2TlIII(CH3) in water where in both cases functionalization gives methyl acetate and methanol. Our calculations suggest that (OAc)TlIII(CH3)2 is thermodynamically and kinetically stable against bond homolysis, heterolysis, protonolysis, and all reductive functionalization pathways. Functionalization is only possible after methyl anion group transfer to TlIII(OAc)3 to give (OAc)2TlIII(CH3). Our calculations suggest that this monomethyl structure is functionalized by acetate dissociation to give a Tl monocation and then a one-step nucleophilic functionalization where water and acetate have competitive transition states.

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“…Überträgt man nun die Vorstellung über den Mechanismus des Zerfalls von MeTl(OAc)2 [5] generell auf Monoalkylthalliumverbindungen, so wird dieser Zusammenhang verständlich : unter der Annahme konstanter Hybridisierung läßt sich die Zunahme von J( 203 ' 205 Tl-iH) mit der Zunahme der positiven Partialladungen am TI-und am a-C-Atom korrelieren. Dadurch wird die durch den Angriff eines Nukleophils am a-CAtom eingeleitete Zersetzung begünstigt, so daß mit zunehmender Partialladung im thallierten Keton dessen "Stabilität" abnimmt.…”

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Reaktion von Hiallium(III)-carboxylaten mit Ketonen / Reactions of Thallium(III) Carboxylates with Ketones

Vollmerhaus

Huber

1981

Zeitschrift Für Naturforschung B

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Abstract In the reaction of ketones RCOCH3 (R = CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, tert-C4H9) with thallium(III) acetate in methanol, thallation at CH3 or at a-C in R has been observed by NMR spectroscopy. J(203/205T1-1H) in RCOCH2X [X = Tl(OCOCH3)2] is nearly independent of R (ca. 1290 Hz), but in R′CHXCOCH3 (R′ = H, CH3, C2H5) it increases with increasing chain length. RCOCH2X and R′CHXCOCH3 decompose to give the corresponding acetoxylated ketones, e.g. CH3COCH2OCOCH3. Analogous thallation products have been observed in the reaction of acetone and C2H5COCH3 with thallium (III) iso-butyrate.

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Kinetik und mechanismus des zerfalls von monomethylthalliumdiacetat in Lösung

Cited by 11 publications

References 9 publications

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂

Mechanisms and Reactivity of Tl(III) Main-Group-Metal–Alkyl Functionalization in Water

Reaktion von Hiallium(III)-carboxylaten mit Ketonen / Reactions of Thallium(III) Carboxylates with Ketones

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Kinetik und mechanismus des zerfalls von monomethylthalliumdiacetat in Lösung

Cited by 11 publications

References 9 publications

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C6H5—CH(OCH3)—CH2Tl(OAc)2

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C6H5—CH(OCH3)—CH2Tl(OAc)2

Mechanisms and Reactivity of Tl(III) Main-Group-Metal–Alkyl Functionalization in Water

Reaktion von Hiallium(III)-carboxylaten mit Ketonen / Reactions of Thallium(III) Carboxylates with Ketones

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Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂

Influence de la coordination du thallium sur la cinétique de décomposition du composé d'oxythallation: C₆H₅—CH(OCH₃)—CH₂Tl(OAc)₂