115565-11-2

Upstream product

• 207920-53-4 K[(MeC(CH₂PPh₂)3)Ru(H)3] 
• 201230-82-2 carbon monoxide 
• 31378-26-4 tris(2,4-pentanedionato)ruthenium(III) 
• 1333-74-0 hydrogen 
• 123-38-6 propionaldehyde 
• 22031-12-5 [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] 
• 65-85-0 benzoic acid 
• 55-21-0 benzamide 
• 106-65-0 Dimethyl succinate 
• 100-51-6 benzyl alcohol 
• 64-18-6 formic acid 
• 141-53-7 sodium formate 
• 554-12-1 propanoic acid methyl ester 

Downstream Products

• 371236-03-2 [(1,1,1-tris(diphenylphosphinomethyl)ethane)Ru(CO)H(H₂)]⁽¹⁺⁾ 

Relevant academic research and scientific papers

Hydrogenation and Reductive Amination of Aldehydes using Triphos Ruthenium Catalysts

An air-stable and readily accessible ruthenium dihydride complex catalyses aldehyde hydrogenation under neutral conditions. A high activity has been shown in a number of examples, and solvent-free conditions are also applicable, which favours industrial-scale applications. The catalyst has also been demonstrated to be active at low catalyst loadings for the reductive amination of aldehydes under mildly acidic conditions. A number of examples of chemoselectivity challenges are also presented in which the catalyst does not reduce carbon?halogen groups, alkene or ketone functionality. The advantage of using the pre-formed complex, Triphos-Ru(CO)H2 (1), over in situ formed catalysts from Triphos and Ru(acac)3 (acac=acetylacetonate) is also shown in terms of both chemoselectivity and activity, in particular this can be seen if low reaction temperatures are used.

Selective homogeneous hydrogenation of biogenic carboxylic acids with [Ru(TriPhos)H]+: A mechanistic study

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.

Catalytic Transformation of Levulinic Acid to 2-Methyltetrahydrofuran Using Ruthenium - N-Triphos Complexes

A series of pre- or in situ-formed ruthenium complexes were assessed for the stepwise catalytic hydrogenation of levulinic acid (LA) to 2-methyltetrahydrofuran (2-MTHF) via γ-valerolactone (γVL) and 1,4-pentanediol (1,4-PDO). Two different catalytic systems based on the branched triphosphine ligands Triphos (CH3C(CH2PPh2)3) and N-triphos (N(CH2PPh2)3) were investigated. The most active catalyst was the preformed ruthenium species [RuH2(PPh3){N(CH2PPh2)3-κ3P}] (5), which gave near quantitative conversion of LA to 1,4-PDO when no acidic additives were present, and 87% 2-MTHF when used in conjunction with HN(Tf)2. Various acidic additives were assessed to promote the final transformation of 1,4-PDO to 2-MTHF; however, only HN(Tf)2 was found to be effective, and NH4PF6 and para-toluenesulfonic acid (p-TsOH) were found to be detrimental. Mechanistic investigations were carried out to explain the observed catalytic trends and importantly showed that PPh3 dissociation from 5 resulted in its improved catalytic reactivity. The presence of acidic additives removes catalytically necessary hydride ligands and may also compete with the substrate for binding to the catalytic metal center, explaining why only an acid with a noncoordinating conjugate base was effective. Crystals suitable for X-ray diffraction experiments were grown for two complexes: [Ru(NCMe)3{N(CH2PPh2)3-κ3P}] (14) and [Ru2(μ-Cl)3{N(CH2PPh2)3-κ3P}2][BPh4] (16). (Chemical Equation Presented).

Highly versatile catalytic hydrogenation of carboxylic and carbonic acid derivatives using a Ru-triphos complex: Molecular control over selectivity and substrate scope

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 complexes [Ru(Triphos)(CO)H2] and [Ru(Triphos)(μ-H)]2 was identified as major deactivation pathways. The former complex results from substrate-dependent decarbonylation and constitutes a major limitation for the substrate scope under the neutral conditions. The deactivation via the carbonyl complex can be suppressed by addition of catalytic amounts of acids comprising non-coordinating anions such as HNTf2 (bis(trifluoromethane)sulfonimide). Although the corresponding cationic cycle shows higher overall barriers of activation, it provides a powerful hydrogenation pathway at elevated temperatures, enabling the selective reduction of primary amides, carbonates, and ureas in high yields. Thus, 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.

Formic acid dehydrogenation catalysed by ruthenium complexes bearing the tripodal ligands triphos and NP3

The selective formic acid dehydrogenation to a mixture of CO2 and H2 was achieved with moderate to good productivities in the presence of homogeneous Ru catalysts bearing the polydentate tripodal ligands 1,1,1-tris-(diphenylphosphinomethyl)ethane (triphos) and tris-[2- (diphenylphosphino)ethyl]amine (NP3), either made in situ from suitable Ru(iii) precursors or as molecular complexes. Preliminary mechanistic studies highlighting subtle differences due to ligand effects in the corresponding systems under study are also presented.

HOMOGENOUS PROCESS FOR THE HYDROGENATION OF CARBOXYLIC ACIDS AND DERIVATIVES THEREOF

A homogenous process for the hydrogenation of the carboxylic acids and/or derivatives thereof in the presence of a catalyst comprising ruthenium, rhodium, iron, osmium or palladium, and an organic phosphine is described in which the hydrogenation is carried out in the presence of at least about 1% by weight water. A process for regenerating a catalyst comprising ruthenium, rhodium, iron, osmium or palladium and an organic phosphine is also described in which the regeneration is carried out in the presence of hydrogen and water.

Mimicking the HDS activity of ruthenium-based catalysts. Homogeneous hydrogenolysis of benzo[b]thiophene

The reaction of [(triphos)RuH(BH4)] (1) in THF with KOBut yields the novel trihydride complex K[(triphos)RuH3] (2) and BH2OBut (triphos = MeC(CH2PPh2)3). The ruthenate complex 2 can also be synthesized by hydrogenation (30 bar of H2) in THF of the tris(acetonitrile) complex [(triphos)Ru(NCMe)3](BPh4)2 (3) in the presence of a 5-fold excess Of BH2OBut at 40 °C, This reaction produces a mixture Of NH2Et, NHEt2, NEt3, and NH3 as a result of MeCN hydrogenation, followed by amine redistribution reactions. Compound 2 is isolated in analytically pure form as [K(C12H24O6)][(triphos)RuH3] (2a) by recrystallization from THF/n-hexane in the presence of 18-crown-6 ether. In the presence of a strong base such as KOBut, both 1 and 3 are effective catalyst precursors for the homogeneous hydrogenolysis of benzo[b]thiophene (BT) to 2-ethylthiophenol (ETP) in THF under mild reaction conditions (>70 °C, 30 bar of H2). The hydrogenolysis rate increases with the concentration of the base, which, depending on the catalyst precursor, may play up to three distinct roles in the catalytic reactions. It promotes the formation and stabilization of the catalytically active species (i.e. the 16e- fragment [(triphos)RuH]-) and speeds up the hydrogenolysis rate, delivering the ETP product into the solution as 2-ethylthiophenolate potassium salt. High-pressure 31P{1H} and 1H NMR experiments (HPNMR) in sapphire tubes sealed by titanium-alloy valves show that the interaction of 2 with BT at ≥ 70 °C in THF-d8 selectively yields the dihydride thiolate complex K[(triphos)Ru(H)2(o-S(C6H4)C2H 5)] (5) under H2 and the vinylthiophenolate complex K[(triphos)Ru(η3-S(C6H6)CH=CH2)] (6) under N2. Compound 6 in THF transforms into 5 by treatment with H2 even at room temperature. Under catalytic conditions at 70 °C, 5 and 2 are the only NMR-detectable species in equilibrium concentrations that depend on the temperature and on the base concentration. The hydrogenolysis mechanism is proposed to involve C-S insertion of ruthenium into the C2-S bond of BT to give a 2-vinylthiophenolate ligand, followed by hydrogenation of the vinyl moiety and reductive elimination of the thiol. This latter step is accelerated by the strong Br?nsted base. The possible similarity in the hydrogenolysis reactions catalyzed by the present soluble complexes to those occurring in the hydrodesulfurization of fossil fuels over Ru-promoted heterogeneous catalysts is discussed.