Topic
Triphos
About: Triphos is a research topic. Over the lifetime, 503 publications have been published within this topic receiving 11105 citations.
Papers published on a yearly basis
Papers
TL;DR: In this paper, a detailed mechanistic study using DFT calculations shows that a sequential series of hydride transfer and protonolysis steps can account for the transformation of CO2 via formate/formic acid to hydroxymethanolate or formaldehyde and finally methanolate/methanol within the coordination sphere of a single Ru-Triphos-fragment.
Abstract: The hydrogenation of CO2 to methanol can be achieved using a single molecular organometallic catalyst. Whereas homogeneous catalysts were previously believed to allow the hydrogenation only via formate esters as stable intermediates, the present mechanistic study demonstrates that the multistep transformation can occur directly on the Ru–Triphos (Triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane) centre. The cationic formate complex [(Triphos)Ru(η2-O2CH)(S)]+ (S = solvent) was identified as the key intermediate, leading to the synthesis of the analogous acetate complex as a robust and stable precursor for the catalytic transformation. A detailed mechanistic study using DFT calculations shows that a sequential series of hydride transfer and protonolysis steps can account for the transformation of CO2via formate/formic acid to hydroxymethanolate/formaldehyde and finally methanolate/methanol within the coordination sphere of a single Ru–Triphos-fragment. All experimental results of the systematic parameter optimisation are fully consistent with this mechanistic picture. Based on these findings, a biphasic system consisting of H2O and 2-MTHF was developed, in which the active cationic Ru-complex resides in the organic phase for recycling and methanol is extracted with the aqueous phase.
320 citations
TL;DR: The complex [Ru(Triphos)(TMM)] provides a unique platform for the rational selection of reaction conditions for the selective hydrogenation of challenging functional groups and opens novel synthetic pathways for the utilization of renewable carbon sources.
Abstract: The complex [Ru(Triphos)(TMM)] (Triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane, TMM = trimethylene methane) provides an efficient catalytic system for the hydrogenation of a broad range of challenging functionalities encompassing carboxylic esters, amides, carboxylic acids, carbonates, and urea derivatives. The key control factor for this unique substrate scope results from selective activation to generate either the neutral species [Ru(Triphos)(Solvent)H2] or the cationic intermediate [Ru(Triphos)(Solvent)(H)(H2)]+ in the presence of an acid additive. Multinuclear NMR spectroscopic studies demonstrated together with DFT investigations that the neutral species generally provides lower energy pathways for the multistep reduction cascades comprising hydrogen transfer to C═O groups and C–O bond cleavage. Carboxylic esters, lactones, anhydrides, secondary amides, and carboxylic acids were hydrogenated in good to excellent yields under these conditions. The formation of the catalytically inactive complexe...
243 citations
TL;DR: The first homogeneous non-noble metal catalyst for the hydrogenation of CO2 to methanol is described andKinetic studies suggest an inner-sphere mechanism, and in situ NMR and MS experiments reveal the formation of the active catalyst through slow removal of the acetylacetonate ligands.
Abstract: Herein we describe the first homogeneous non-noble metal catalyst for the hydrogenation of CO2 to methanol. The catalyst is formed in situ from [Co(acac)3], Triphos, and HNTf2 and enables the reaction to be performed at 100 °C without a decrease in activity. Kinetic studies suggest an inner-sphere mechanism, and in situ NMR and MS experiments reveal the formation of the active catalyst through slow removal of the acetylacetonate ligands.
242 citations
TL;DR: A mechanistic study on the homogeneously ruthenium/phosphine catalyzed transformations of levulinic acid and itaconic acid to the corresponding lactones, diols, and cyclic ethers, forming a rational basis for further catalyst development.
Abstract: Selective hydrogenation of biogenic carboxylic acids is an important transformation for biorefinery concepts based on platform chemicals. We herein report a mechanistic study on the homogeneously ruthenium/phosphine catalyzed transformations of levulinic acid (LA) and itaconic acid (IA) to the corresponding lactones, diols, and cyclic ethers. A density functional theory (DFT) study was performed and corroborated with experimental data from catalytic processes and NMR investigations. For [Ru(TriPhos)H](+) as the catalytically active unit, a common mechanistic pathway for the reduction of the C═O functionality in aldehydes, ketones, lactones, and even free carboxylic acids could be identified. Hydride transfer from the Ru-H group to the carbonyl or carboxyl carbon is followed by protonation of the resulting Ru-O unit via σ-bond metathesis from a coordinated dihydrogen molecule. The energetic spans for the reduction of the different functional groups increase in the order aldehyde < ketone < lactone ≈ carboxylic acid. This reactivity pattern as well as the absolute values are in full agreement with experimentally observed activities and selectivities, forming a rational basis for further catalyst development.
225 citations
TL;DR: The catalytic properties of the transition-metal complexes depend on the appropriate choice of ligand, solvent, temperature, and counteranion as mentioned in this paper, and the X-ray crystal structure of one catalyst, [PdCl(triphos)](CF3SO3).
200 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 2 |
| 2024 | 2 |
| 2023 | 6 |
| 2022 | 4 |
| 2021 | 6 |
| 2020 | 11 |