123-15-9Relevant articles and documents
Modification of rhodium catalyst with stibines for hydroformylation of 1-pentene
Sharma, Pankaj,Arias, Jose Luis,Vasquez, Jaime,Gomez, Valente,Guiterrez, Rene
, p. 681 - 684 (2007)
Homogeneous hydroformylation of 1-pentene under synthesis gas experimental conditions was studied using RhClCO(PPh3)2 complex with different triarylstibines. Three different stibine ligands SbR3 [where R = 2,4,6-mesityl (TMS), 2-furyl (TFS), 2-N,N-dimethylbenzylamine (TDMBAS)], have been tested. It is interesting to note that 2:1 addition of these stibine ligands to the RhClCO(PPh3)2 complex catalyst increases the aldehydes yields with an appreciable n:iso ratio. The catalytic activity of the system shows a TDMBAS > TMS > TFS pattern which indicates that not only basicity of the ligand alone is playing a role in the activity but the steric effect is also very important, and it is combination of these two factors that contributes to the resulting catalytical activity. The maximum yield of aldehydes obtained were 98.7% with n/iso = 1.4 when RhClCO(PPh3)2 + TFS system was used and 93.7% with n/iso = 2.43 when TDMBAS ligand was studied.
Pyridine-triazole ligands for copper-catalyzed aerobic alcohol oxidation
Thongkam, Pech,Jindabot, Sudarat,Prabpai, Samran,Kongsaeree, Palangpon,Wititsuwannakul, Taveechai,Surawatanawong, Panida,Sangtrirutnugul, Preeyanuch
, p. 55847 - 55855 (2015)
A series of Cu(NN′)2(OTf)2 complexes containing pyridine-triazole ligands [OTf = OSO2CF3; NN′ = NN′Ph (1), NN′hex (2), NN′py (3)] with different substituents at the triazole N4 position or 2,2′-bipyridine (bpy; 4) have been synthesized. Crystal structures of 1 and 3 reveal a trans-isomer with strong preference for regular-type triazole coordination (for 3) whereas the Cu-bipyridine complex 4 is more stable in a cis-form. Cyclic voltammetry of 1-4 suggest that the electron-donating strength follows the trend: bpy > NN′py > NN′hex ～ NN′Ph. The catalyst systems consisting of 5 mol% Cu(OTf)2/NN′/TEMPO (TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxy) in the presence of 2 × 2.0 cm2 Cu0 sheets as a reducing agent and 10 mol% N-methylimidazole (NMI) exhibit good activities for aerobic oxidation of benzyl alcohol to benzaldehyde. Catalytic studies have shown that the activities were higher with more electron-rich N-based ligands. Furthermore, oxidation of aliphatic alcohols such as 1-hexanol and 2-methyl-1-pentanol using the Cu catalyst system with the NN′py ligand at room temperature afforded the corresponding aldehydes in >99% and 46% yields, respectively after 24 h.
1-Pentene Hydroformylation Catalyzed by Polymer-Bound Ruthenium Complexes
Pittman, Charles U.,Wilemon, Gary M.
, p. 1901 - 1905 (1981)
Polymer-bound ruthenium hydroformylation catalysts were prepared by reacting diphenylphosphinated styrene-1percent divinylbenzene resins with Ru(CO)3(PPh3)2 under a carbon monoxide atmosphere.Resins with 29percent and 5percent ring-substitution loading levels of phosphine were prepared, and resins with P/Ru ratios of 3.1, 6.7, and 11.3 were made with the 29percent phosphine loading.These resins functioned as 1-pentene hydroformylation catalysts and were compared to the homogeneous use of Ru(CO)3(PPh3)2 as the catalyst.No olefin isomerization occured.The resin catalysts with P/Ru ratios of 3.1 and 6.7 at 29percent loading gave higher n/b aldehyde selectivities (3.5-3.8) than the homogeneous catalyst when employed at P/Ru ratios of 20 but not as high as was achieved by using Ru(CO)3(PPh3)2 in molten PPh3 (5.1).The n/b selectivity was discussed in terms of the equilibrium between (polymer-PPh2)2RuH2(alkene)(CO) and polymer-PPh2RuH2(alkene)(CO)2 within the resin matrix where phosphine loading, P/Ru, ligand mobility, and swelling play contributing roles.The novel 1,1'-bis(diphenylphosphino)ferrocene ligand induced higher n/b selectivities than PPh3 in homogeneous Ru-catalyzed reactions.
Recycling of two molecular catalysts in the hydroformylation/aldol condensation tandem reaction using one multiphase system
Leitner, Walter,Strohmann, Marc,Vorholt, Andreas J.,Vossen, Jeroen T.
, p. 8444 - 8451 (2020)
Tandem reactions are of great importance to efficiently execute multiple conversions in one synthesis step. Herein we present a multiphase system for the hydroformylation/aldol condensation, which is able to recycle both optimized catalysts multiple times. The system consists of an organometallic rhodium/sulfoXantphos hydroformylation catalyst and basic NaOH as aldol condensation initiator, which are both immobilized in a polyethylene glycol phase. Under reaction conditions, NaOH is converted to sodium formate, which is still able to catalyse the aldol condensation. The reaction and recycling are demonstrated by the conversion of 1-pentene to the corresponding aldol product in a recycling experiment. During nine consecutive runs, no significant loss of activity is found with an overall TON of 8700 in regard to the rhodium catalyst and an average rhodium leaching of only of 0.07% per run is observed.
The continuous self aldol condensation of propionaldehyde in supercritical carbon dioxide: A highly selective catalytic route to 2-methylpentenal
Stevens, James G.,Bourne, Richard A.,Poliakoff, Martyn
, p. 409 - 416 (2009)
The aldol reactions of propionaldehyde and butyraldehyde have been explored in supercritical CO2, scCO2, using an automated continuous flow reactor. The reaction was found to proceed over a variety of heterogeneous acidic and basic catalysts and with increased selectivity compared to using neat reactants.
Synthesis of novel rhodium phosphite catalysts for efficient and selective isomerization-hydroformylation reactions
Piras, Irene,Jennerjahn, Reiko,Jackstell, Ralf,Baumann, Wolfgang,Spannenberg, Anke,Franke, Robert,Wiese, Klaus-Diether,Beller, Matthias
, p. 479 - 486 (2010)
New modular H8-BINOL-based phosphite ligands have been synthesized. High activity and regioselectivity has been achieved in the rhodium-catalyzed isomerization-hydroformylation of internal olefins. The active catalysts have been characterized by in situ NMR studies.
n-pentane carbonylation with CO on sulfated zirconia: An in situ solid-state 13C NMR study
Luzgin,Stepanov,Shmachkova,Kotsarenko
, p. 23 - 25 (2001)
Using 13C CP/MAS NMR, the first evidence has been obtained for n-pentane carbonylation with carbon monoxide into C6 aldehydes, ketones and carboxylic acids on a sulfated zirconia catalyst.
Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
, (2021/12/23)
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
Catalyst composition containing bidentate phosphine ligand and application thereof
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Paragraph 0068; 0081-0084, (2021/11/03)
The catalyst composition comprises a bidentate phosphine ligand and a rhodium complex, wherein the skeleton of the bidentate phosphine ligand not only has C. 2 The symmetry and the appropriate rigidity, and the phosphine ligand derived based on the skeleton can provide effective steric hindrance around the catalyst center metal, so that the selectivity of the catalyst can be remarkably improved, the aldehyde yield is not lower 92% when the catalyst combination is applied to the hydroformylation reaction, and the selectivity of n-aldehyde is not lower 90%. In addition, the raw materials olefins with different structures can obtain outstanding reaction rate and normal aldehyde selectivity as compared with the existing catalyst systems, and can be suitable for the hydroformylation reaction of more types of olefins.
Zeolite-Encaged Isolated Platinum Ions Enable Heterolytic Dihydrogen Activation and Selective Hydrogenations
Dai, Weili,Deng, Xin,Guan, Naijia,Li, Landong,Liu, Runze,Ma, Ding,Qin, Bin,Qin, Xuetao,Wu, Guangjun
supporting information, p. 20898 - 20906 (2021/12/14)
Understanding the unique behaviors of atomically dispersed catalysts and the origin thereof is a challenging topic. Herein, we demonstrate a facile strategy to encapsulate Ptδ+ species within Y zeolite and reveal the nature of selective hydrogenation over a Pt@Y model catalyst. The unique configuration of Pt@Y, namely atomically dispersed Ptδ+ stabilized by the surrounding oxygen atoms of six-membered rings shared by sodalite cages and supercages, enables the exclusive heterolytic activation of dihydrogen over Ptδ+···O2- units, resembling the well-known classical Lewis pairs. The charged hydrogen species, i.e., H+ and Hδ-, are active reagents for selective hydrogenations, and therefore, the Pt@Y catalyst exhibits remarkable performance in the selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols and of nitroarenes to arylamines.
