ChemInform Abstract: Oxidative Carbonylation of Benzene and Its Derivatives in the Presence of Rhodium, Palladium, and Copper Compounds.

Kalinovskii, I. O.; Лещева, А. А.; Kuteinikova, M. M.; Gel'bshtein, A.I.

doi:10.1002/chin.199039141

Cited by 3 publications

(12 citation statements)

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“…Taken together, these results demonstrate that Rh is active as Rh(III) but undergoes reduction to Rh(I) during the course of reaction and must be reoxidized, and that this process occurs most effectively in the presence of NH 4 VO 3 and O 2 . These findings are in agreement with those reported earlier by Kalinovskii et al [6].…”

Section: Scoping Experimentssupporting

confidence: 95%

“…Unexpectedly, though, the p/m isomer ratio decreased with increasing O 2 partial pressure. The effect of O 2 partial pressure on the yield of toluic acid suggests that the re-oxidation of Rh(I) to Rh(III) is rate limiting, rather than C H bond activation in agreement with findings of Kalinovskii et al [6]. Moreover, spectroscopic evidence discussed below suggest that while the oxidation of Rh(I) by VO x species in solution is rapid, the reoxidation of the resulting VO x−1 species by O 2 is slow.…”

Section: Co and O 2 Partial Pressuressupporting

confidence: 82%

“…Since Rh(III) is reduced to Rh(I) and Pd(II) is reduced to Pd(0) in the course of the reaction, it was necessary to provide a means for reoxidizing the reduced metal. In the case of Pd, this could be done effectively using Cu(II) cations together with O 2 in a Wacker-type process [6]. FeC 2 O 4 , (NH 4 ) 6 Mo 7 O 24 , (NH 4 )VO 3 , and V 2 O 5 in combination with O 2 were also shown to work effectively as oxidants for both Pd and Rh [7].…”

Section: Introductionmentioning

confidence: 97%

“…In subsequent studies, Kalinovskii and coworkers have shown that the oxidative carbonylation of arenes can also be catalyzed using rhodium(III) or palladium(II) cations [6][7][8][9], and they have proposed a mechanism for the synthesis of toluic acid from toluene [9]. Since Rh(III) is reduced to Rh(I) and Pd(II) is reduced to Pd(0) in the course of the reaction, it was necessary to provide a means for reoxidizing the reduced metal.…”

Section: Introductionmentioning

confidence: 98%

“…Rh was chosen over Pd as the catalyst because of its higher selectivity to p-toluic acid and NH 4 VO 3 /O 2 was chosen for reoxidation of the catalyst because of its demonstrated effectiveness [6]. Additional components of the reaction system were trifluoroacetic acid (TFAH) and trifluoroacetic anhydride (TFAA).…”

Section: Introductionmentioning

confidence: 99%

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Oxidative carbonylation of toluene to p-toluic acid catalyzed by rhodium in the presence of vanadium and oxygen

Zakzeski

Bell

2007

Journal of Molecular Catalysis A: Chemical

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Section: Scoping Experimentssupporting

confidence: 95%

Section: Co and O 2 Partial Pressuressupporting

confidence: 82%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Oxidative carbonylation of toluene to p-toluic acid catalyzed by rhodium in the presence of vanadium and oxygen

Zakzeski

Bell

2007

Journal of Molecular Catalysis A: Chemical

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Effects of Ligand Composition on the Oxidative Carbonylation of Toluene to Toluic Acid Catalyzed by Rh(III) Complexes

et al. 2009

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Experimental and theoretical studies were conducted to investigate the influence of anionic ligands (e.g., CF(3)COO(-), CH(3)SO(3)(-)) on the catalytic activity and selectivity of Rh(III) in the oxidative carbonylation of toluene to toluic acid. The catalyst activity was found to pass through a maximum as the pK(a) of the conjugate Brønsted acid decreases from 4.63 to -2.00, with the maximum activity occurring at pK(a) = 0.35, corresponding to CClF(2)COOH. The theoretical analysis showed that the strength of toluene coordination increases with decreasing basicity of the anion (i.e., decreasing pK(a) of the corresponding acid). In contrast, the activation barrier for C-H activation increases with decreasing ligand pK(a). The experimentally observed effect of anion composition on catalyst activity can be explained using calculations of the apparent rate coefficient for toluene activation based on density functional theory and transition state theory. The ratio of p- to m-toluic acid formed increases with decreasing acid pK(a) and passes through a maximum for pK(a) = 0, corresponding to CF(3)COOH. The effect of anion composition on the isomer selectivity is attributed to changes in the charge density on the Rh(III) cation, which in turn affect the distribution of charge on the para and meta carbon atoms of the aromatic ring.

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Theoretical Analysis of the Mechanism for the Oxidative Carbonylation of Toluene to p-Toluic Acid by Rhodium Complexes

Zheng

Bell

2008

J. Phys. Chem. C

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Density functional theory has been used to investigate the mechanism and kinetics of the liquid-phase, oxidative carbonylation of toluene to p-toluic acid (C 7 H 8 + CO + 1 / 2 O 2 f p-C 7 H 6 COOH + H 2 O) catalyzed by Rh(III) cations. In toluene solution containing trifluoroacetic acid and dissolved CO, Rh(III) is coordinated to three trifluoroacetate (TFA) anions and two CO molecules as Rh(CO) 2 (TFA) 3 . The oxidative carbonylation of toluene is initiated by the addition of toluene across one of the Rh-O bonds of Rh(CO) 2 (TFA) 3 to form (C 7 H 7 )Rh-(CO) 2 (TFAH)(TFA) 2 . The latter species undergoes isomerization and CO migration to produce (C 7 H 7 CO)-Rh(CO)(TFAH)(TFA) 2 , which then coordinates another molecule of CO. The mixed anhydride of toluic and tirfluoroacetic acid, C 7 H 7 C(O)O(O)CCF 3 and Rh(CO) 3 (TFA), are produced by reductive elimination from (C 7 H 7 CO)Rh(CO) 2 (TFAH)(TFA) 2 . Para-toluic acid is then formed by hydrolysis of C 7 H 7 C(O)O(O)CCF 3 . The proposed reaction mechanism explains many of the observations reported in our previous experimental work (Zakzeski, J. J.; Bell, A. T. J. Mol. Catal. A 2007, 276, 8) and, in particular, the effect of temperature on the ratio of p-to m-toluic acid, the effects of H 2 O and the partial pressure of CO on the loss of catalyst activity, and the effect of Rh concentration on the formation of a catalytically inactive Rh dimer species.

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ChemInform Abstract: Oxidative Carbonylation of Benzene and Its Derivatives in the Presence of Rhodium, Palladium, and Copper Compounds.

Abstract: 141ChemInform Abstract The oxidative carbonylation of arenes such as benzene (I) or toluene (IV) to give the corresponding benzoic acids is studied in detail. (Mechanism).

Cited by 3 publications

References 0 publications

Oxidative carbonylation of toluene to p-toluic acid catalyzed by rhodium in the presence of vanadium and oxygen

Oxidative carbonylation of toluene to p-toluic acid catalyzed by rhodium in the presence of vanadium and oxygen

Effects of Ligand Composition on the Oxidative Carbonylation of Toluene to Toluic Acid Catalyzed by Rh(III) Complexes

Theoretical Analysis of the Mechanism for the Oxidative Carbonylation of Toluene to p-Toluic Acid by Rhodium Complexes

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