7786-29-0Relevant academic research and scientific papers
Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
supporting information, p. 8040 - 8046 (2021/11/01)
As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
Methyl-modified cage-type phosphorus ligand and preparation method thereof Preparation method and application thereof
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Paragraph 0075-0084; 0087-0088, (2021/09/15)
The invention discloses a methyl-modified cage-type phosphorus ligand, a preparation method and application thereof, in particular to a synthesis design, wherein methyl is further introduced on a phenyl ring of triphenylphosphine, and a methyl-modified cage-type phosphorus ligand is synthesized, and when a methyl meta-substituted cage-type phosphorus ligand is used as a hydroformylation reaction catalyst the proportion of n-structural aldehyde and isomeric aldehyde is 2.6. TOF-1 The methyl-substituted cage-type phosphorus ligand is excellent in performance, stable in property and recyclable, has excellent substrate applicability in the hydroformylation catalytic reaction, has a good industrial application prospect, and has very important significance in metal organic catalysis.
ALDEHYDE GENERATION VIA ALKENE HYDROFORMYLATION
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Paragraph 0035; 0079-0081, (2021/09/26)
Aldehyde generation includes providing a first input stream, a second input, and an alkene substrate to a reactor system. The first input stream includes a catalyst, a ligand, and an organic solvent. The second input stream includes a mixture of carbon monoxide (CO) and hydrogen gas (H2). The alkene substrate is in either gaseous form or liquid form, the liquid form of the alkene substrate being provided with the first input stream, the gaseous form of the alkene substrate being provided with the second input stream. The reactor system includes a first reactor and a second reactor, where the second reactor is gas permeable and positioned within the first reactor.
Insight into decomposition of formic acid to syngas required for Rh-catalyzed hydroformylation of olefins
Liu, Lei,Chen, Xiao-Chao,Yang, Shu-Qing,Yao, Yin-Qing,Lu, Yong,Liu, Ye
, p. 406 - 415 (2020/12/07)
Formic acid (FA) is one kind of important bulk chemicals, which is recognized as a sustainable and eco-friendly energy carrier to transport H2 via dehydrogenation or CO via decarbonylation. Expectantly, FA upon decomposition into H2 and CO could be used as the syngas alternative for hydroformylation. In this paper, the behaviors of FA to release H2 as well as CO following the distinct pathways were carefully investigated for the first time, and then established a new hydroformylation protocol free of syngas. It was found that the atmospheric hydroformylation of olefins with formic acid (FA) as syngas alternative was smoothly fulfilled over Xantphos (L1) modified Rh-catalyst under mild conditions (80 °C, Rh concentration 1 mol %, 14 h), resulting in >90% conversion of the olefins along with the high selectivity to the target aldehydes (>93%). By using FA as syngas source, the side-reaction of olefin-hydrogenation was greatly depressed. The in situ FT-IR and the high-pressure 1H NMR spectroscopic analyses were applied to reveal how FA behaves dually as CO surrogate and hydrogen source over L1-Rh(acac)(CO)2 catalytic system, based on which the deeply insight into the catalytic mechanism of hydroformylation of olefins with FA as syngas alternative was offered.
Rh-catalyzed highly regioselective hydroformylation to linear aldehydes by employing porous organic polymer as a ligand
Wang, Zhaozhan,Yang, Yong
, p. 29263 - 29267 (2020/10/06)
In this work, we developed a new structural porous organic polymer containing biphosphoramidite unit, which can be used as a solid bidentate phosphorous ligand for rhodium-catalyzed solvent-free higher olefins hydroformylation. The resultant catalyst demonstrated unprecedently high regioselectivity to linear aldehydes and could be readily recovered for successive reuses with good stability in both catalytic activity and regioselectivity. This journal is
Bimetallic Paddlewheel-type Dirhodium(II,II) Acetate and Formamidinate Complexes: Synthesis, Structure, Electrochemistry, and Hydroformylation Activity
Casimiro, Anna,De Doncker, Stephen,Kotze, Izak A.,Ngubane, Siyabonga,Smith, Gregory S.
, p. 12928 - 12940 (2020/09/15)
Classical hydroformylation catalysts use mononuclear rhodium(I) complexes as precursors; however, very few examples of bimetallic systems have been reported. Herein, we report fully substituted dirhodium(II,II) complexes (C1-C6) containing acetate and diphenylformamidinate bridging ligands (L1-L4). The structure and geometry around these paddlewheel-type, bimetallic cores were confirmed by single-crystal X-ray diffraction. The complexes C3-C6 show electrochemical redox reactions, with the expected reduction (Rh24+/3+) and two oxidation (Rh24+/5+ and Rh25+/6+) electron transfer processes. Furthermore, the bimetallic complexes were evaluated as catalyst precursors for the hydroformylation of 1-octene, with the acetate-containing complexes (C1 and C2) showing near quantitative conversion (>99%) of 1-octene, excellent activity and chemoselectivity toward aldehydes (>98%), with moderate regioselectivity toward linear products. Replacement of the acetate with diphenylformamidinate ligands (complexes C3-C6) yielded moderate-to-good chemoselectivity and regioselectivity, favoring linear aldehydes.
Anisole: A further step to sustainable hydroformylation
Delolo, Fábio G.,Dos Santos, Eduardo N.,Gusevskaya, Elena V.
supporting information, p. 1091 - 1098 (2019/03/12)
Hydroformylation, also known as the "oxo" process, is a major industrial process that employs rhodium or cobalt catalysts in solution; therefore the solvent of this process is a critical issue for its sustainability. Although several innovative solutions have been proposed recently, traditional fossil-derived solvents dominate the scenario for this reaction. In this paper, we studied a series of solvents considered more sustainable in recent ranks in the hydroformylation of a series of olefins. Anisole, a solvent with an impressive sustainability rank and very scarcely exploited in hydroformylation, proved to be an excellent alternative for this reaction.
XL-Xantphos: Design and Synthesis of a Mechanistic Probe of Xantphos O-Coordination in Catalytic Reactions
Whiteker, Gregory T.,Li, Fangzheng,Froese, Robert D. J.,Tulchinsky, Michael L.,Hazari, Amaruka,Klosin, Jerzy
supporting information, p. 2233 - 2238 (2019/05/21)
The synthesis and characterization of an analog of the Xantphos ligand that is geometrically incapable of coordination of the xanthene bridging oxygen atom is reported. This new ligand, XL-Xantphos, ((9,9-dimethyl-9H-xanthene-4,5-diyl)bis(4,1-phenylene))bis(diphenylphosphane), was studied in homogeneous, catalytic reactions for comparison with Xantphos. The XL-Xantphos ligand performed essentially identically to Xantphos in Rh-catalyzed hydroformylation of 1-octene, which suggests that the high regioselectivity for linear aldehyde is due to the large bite angle of these ligands and is not influenced by oxygen coordination to the metal. The Pd-catalyzed amidocarbonylation of 4-bromoanisole with dimethylhydroxylamine hydrochloride similarly showed no difference between Xantphos and XL-Xantphos. Computations on Pd(II) phosphine complexes at the DLPNO-CCSD(T) level of theory indicated that these ligands have different preferences for cis and trans coordination modes. The XL-Xantphos ligand has a thermodynamic preference for trans-chelated structures, whereas the cis-[(Xantphos)PdCl2] isomer was calculated to be thermodynamically more stable than its trans isomer. Given the key role of d8 square planar Pd intermediates in many catalytic cycles, the greater preference of Xantphos to form cis chelates may indeed be a factor which has made this ligand particularly effective.
Porous organic polymer supported rhodium as a reusable heterogeneous catalyst for hydroformylation of olefins
Jia, Xiaofei,Liang, Zuyu,Chen, Jianbin,Lv, Jinhe,Zhang, Kai,Gao, Mingjie,Zong, Lingbo,Xie, Congxia
supporting information, p. 2147 - 2150 (2019/03/26)
A new porous organic polymer has been prepared via copolymerization of divinyl-functionalized phosphoramidite ligand and tris(4-vinylphenyl)phosphine. The porous polymer was loaded with Rh(acac)CO2 to yield a supported Rh catalyst, which demonstrated good regioselectivity (l/b = 6.7-52.8) and high catalytic activity (TON up to 45.3 × 104) in hydroformylation of terminal and internal olefins. Remarkably, the heterogeneous catalyst can be reused at least 10 cycles without losing activity and selectivity in hydroformylation of 1-hexene.
A new air-stable and reusable tetraphosphine ligand for rhodium-catalyzed hydroformylation of terminal olefins at low temperature
Zhou, Fanding,Zhang, Lin,Wu, Qianhui,Guo, Fuya,Tang, Songbai,Xu, Bin,Yuan, Maolin,Fu, Haiyan,Li, Ruixiang,Zheng, Xueli,Chen, Hua
, (2018/11/23)
Tetraphosphine and bisphosphine ligands were synthesized, characterized and employed in Rh-catalyzed hydroformylation of 1-octene and 1-hexene. Conversion of over 97.7% and aldehyde yield of 94.1% were achieved at 60°C, 20?bar. This remarkable performance could also be retained at lower temperature (i.e. 40°C) by prolonging the reaction time. The tetraphosphine ligand-modified Rh catalyst could be reused for at least seven successive runs with catalytic activity and selectivity almost unchanged; the catalyst was separated from the products and recycled directly in homogeneous hydroformylation, indicating that the catalyst might have good stability. 31P NMR and high-resolution mass spectral characterization hinted that the reason for the reusability of the catalyst might be that the tetraphosphine ligand is relatively air-stable and is probably slowly oxidized during the recycling runs. The tetraphosphine ligand has four phosphorus atoms to be partially oxidized and could still coordinate with the Rh center via the unoxidized phosphorus atoms to stabilize the catalyst, based on the multiple chelating modes of the tetraphosphine ligand. Hence, the catalytic activity and selectivity could be retained for a certain number of runs.
