Rhodium-catalyzed reductive carbonylation of methanol

Moloy, Kenneth G.; Wegman, R. W.

doi:10.1021/om00114a025

Cited by 58 publications

(49 citation statements)

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“…The products are very easily isolated by evaporation of the solvent and washing of the residues with diethyl ether. Compounds 6 ± 8 exhibit, as expected, one strong n(CO) absorption in the IR spectrum, which is comparable with those reported for trans-[(PR 3 ) 2 Rh(CO)X], [11,13] but lower than that of the cis-[(dppe)Rh(CO)I] (dppe 1,2-bis(diphenylphosphino)ethane), [14] for trans coordination. The monomeric nature of these complexes can be concluded from the mass spectra.…”

Section: Resultssupporting

confidence: 86%

New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

et al. 2002

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The new diphosphine ligands Ph2PC6H4C(O)X(CH2)2OC(O)C6H4PPh2 (1: X=NH; 2: X=NPh; 3: X=O) and Ph2PC6H4C(O)O(CH2)2O(CH2)2OC(O)C6H4PPh2 (5) as well as the monophosphine ligand Ph2PC6H4C(O)X(CH2)2OH (4) have been prepared from 2‐diphenylphosphinobenzoic acid and the corresponding amino alcohols or diols. Coordination of the diphosphine ligands to rhodium, iridium, and platinum resulted in the formation of the square‐planar complexes [(PP)Rh(CO)Cl] (6: PP=1; 7: PP=2; 8: PP=3), [(PP)Rh(CO)Cl]2 (9: PP=5), [(P‐P)Ir(cod)Cl] (10: PP=1; 11: PP=2; 12: PP=3), [(PP)Ir(CO)Cl] (13: PP=1; 14: PP=2; 15: PP=3), and [(PP)PtI2] (18: PP=2). In all complexes, the diphosphine ligands are trans coordinated to the metal center, thanks to the large spacer groups, which allow the two phosphorus atoms to occupy opposite positions in the square‐planar coordination geometry. The trans coordination is demonstrated unambiguously by the single‐crystal X‐ray structure analysis of complex 18. In the case of the diphosphine ligand 5, the spacer group is so large that dinuclear complexes with ligand 5 in bridging positions are formed, maintaining the trans coordination of the P atoms on each metal center, as shown by the crystal structure analysis of 9. The monophosphine ligand 4 reacts with [{Ir(cod)Cl}2] (cod=cyclooctadiene) to give the simple derivative [(4)Ir(cod)Cl] (16) which is converted into the carbonyl complex [(4)Ir(CO)2Cl] (17) with carbon monoxide. The crystal structure analysis of 16 also reveals a square‐planar coordination geometry in which the phosphine ligand occupies a position cis with respect to the chloro ligand. The diphosphine ligands 1, 2, 3, and 5 have been tested as cocatalysts in combination with the catalyst precursors [{Rh(CO)2Cl}2] and [{Ir(cod)Cl}2] or [H2IrCl6] for the carbonylation of methanol at 170 °C and 22 bar CO. The best results (TON 800 after 15 min) are obtained for the combination 2/[{Rh(CO)2Cl}2]. After the catalytic reaction, complex 7 is identified in the reaction mixture and can be isolated; it is active for further runs without loss of catalytic activity.

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Section: Resultssupporting

confidence: 86%

New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

et al. 2002

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“…Indeed, trans-[Rh(PEt 3 ) 2 (CO)Cl] turned out to be a very active catalyst precursor for AcOH production [9]. Complexes containing P,P-linked bis[phosphine] ligands have also been studied as catalysts for the carbonylation of MeOH [10] [11], they are in general more stable than their complexes containing unlinked bis(monophosphine) analogues. However, since complexes containing P,P-linked bis[phosphines] are usually cis-configured, they are less active than the trans-configured bis(monophosphine) complexes [11].…”

mentioning

confidence: 99%

Square‐Planar Carbonylchlororhodium(I) Complexes Containing trans‐Spanning Diphosphine Ligands as Catalysts for the Carbonylation of Methanol

Burger

Therrien

Süß‐Fink

2005

Helvetica Chimica Acta

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Dedicated to Professor AndreÂ Merbach on the occasion of this 65th birthdayThe rhodium(I) complexes trans-[Rh(diphos)(CO)Cl] 7 (diphos pbpb), 8 (diphos nbpb), and 9 (diphos cbpb) were synthesized (Scheme 4) and used as catalysts for the carbonylation of MeOH to AcOH (Scheme 1). The trans coordination imposed by the rigid C-spacer framework of the diphos ligands pbpb, nbpb, and cbpb, demonstrated by 31 P-NMR and IR spectroscopy of 7 ± 9 and unambiguously confirmed by singlecrystal X-ray structure analysis of 7, improved the thermal stability of the rhodium(I) system under carbonylation conditions and, hence, the catalytic performance of the complexes. For the catalytic carbonylation of MeOH, the active catalyst could be prepared in situ from the mixture of [Rh(CO) 2 Cl] 2 and the corresponding diphos ligand pbpb, nbpb, or cbpb, giving the same results as carbonylation in the presence of the isolated complexes 7, 8 or 9 (see Table). The highest activity was observed for complex 7 (or the mixture [Rh(CO) 2 Cl] 2 / pbpb, the catalytic turnover number (TON) being 950 after 15 min (1708, 22 bar). The anion cis-[Rh(CO) 2 I 2 ] À was found to be the initial catalytically active species [3]. As the rate-determining step of the catalytic cycle is the oxidative addition of MeI to cis-[Rh(CO) 2 I 2 ] À [4], electron enrichment at the metal center is expected to facilitate this step and to improve the rate of AcOH formation. Consequently, square-planar rhodium(I) complexes with ligands that increase the electron density at the Rh-atom have been developed and studied as catalysts; they give better or at least comparable activities than the original Monsanto catalyst [5 ± 8]. Introduction. ± The carbonylation of MeOH to generate AcOH is one of the most important homogeneously catalyzed industrial processes [1] (Scheme 1). The production of AcOH by the

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“…For background literature on the catalytic activity of rhodiumphosphane compounds, see: Carraz et al (2000); Moloy & Wegman (1989); Bonati & Wilkinson (1964). For related rhodium compounds, see : Brink et al (2007); Erasmus & Conradie (2011); Leipoldt et al (1978); Steynberg et al (1987).…”

Section: Related Literaturementioning

confidence: 99%

“…This study is part of ongoing research into induced effects of various phosphanes coordinated to Rh(I) centers. Previous work illustrating the catalytic importance of the rhodium(I) square-planar moieties has been conducted on rhodium mono-and di-phosphane complexes containing the symmetrical bidentate ligand, acac (acac = acetylacetonate) (Moloy and Wegman, 1989). Symmetrical di-phosphane ligands result in the production of acetaldehyde, whereas unsymmetrical diphosphane ligands are more stable and efficient catalysts for the carbonylation of methanol to acetic acid (Carraz et al, 2000).…”

Section: à3mentioning

confidence: 99%

(Acetylacetonato-κ²O,O′)carbonyl[tris(4-chlorophenyl)phosphane-κP]rhodium(I)

Antonels

Meijboom

2012

Acta Cryst E

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The title compound, [Rh(C5H7O2)(C18H12Cl3P)(CO)], contains the bidentate acetylacetonate ligand coordinated to the RhIatom, forming a chelate ring [Rh—O = 2.0327 (15) and 2.0613 (14) Å]. The RhIatom is additionally coordinated by one P [Rh—P = 2.2281 (6) Å] and one carbonyl C [Rh—C = 1.812 (2) Å] atom, resulting in a slightly distorted square-planar geometry. The molecules are packed to minimize steric hindrance with the phosphanes positioned above and below the slightly distorted square geometrical plane.

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Rhodium-catalyzed reductive carbonylation of methanol

Cited by 58 publications

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New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

Square‐Planar Carbonylchlororhodium(I) Complexes Containing trans‐Spanning Diphosphine Ligands as Catalysts for the Carbonylation of Methanol

(Acetylacetonato-κ²O,O′)carbonyl[tris(4-chlorophenyl)phosphane-κP]rhodium(I)

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Rhodium-catalyzed reductive carbonylation of methanol

Cited by 58 publications

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New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

New Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol

Square‐Planar Carbonylchlororhodium(I) Complexes Containing trans‐Spanning Diphosphine Ligands as Catalysts for the Carbonylation of Methanol

(Acetylacetonato-κ2O,O′)carbonyl[tris(4-chlorophenyl)phosphane-κP]rhodium(I)

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(Acetylacetonato-κ²O,O′)carbonyl[tris(4-chlorophenyl)phosphane-κP]rhodium(I)