- Chromium-catalysed efficient: N -formylation of amines with a recyclable polyoxometalate-supported green catalyst
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A simple and efficient protocol for the formylation of amines with formic acid, catalyzed by a polyoxometalate-based chromium catalyst, is described. Notably, this method shows excellent activity and chemoselectivity for the formylation of primary amines; diamines have also been successfully employed. Importantly, the chromium catalyst is potentially non-toxic, environmentally benign and safer than the widely used high valence chromium catalysts such as CrO3 and K2Cr2O7. The catalyst can be recycled several times with a negligible impact on activity. Finally, a plausible mechanism is provided based on the observation of intermediate and control experiments.
- Dan, Demin,Chen, Fubo,Zhao, Whenshu,Yu, Han,Han, Sheng,Wei, Yongge
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supporting information
p. 90 - 94
(2021/01/11)
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- An efficient way for the: N -formylation of amines by inorganic-ligand supported iron catalysis
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The first example of an inorganic-ligand supported iron(iii) catalysed coupling of formic acid and amines to form formamides is reported. The pure inorganic catalyst (NH4)3[FeMo6O18(OH)6] (1), which consists of a central FeIII single-atomic core supported within a cycle-shaped inorganic ligand consisting of six MoVIO6 octahedra, shows excellent activity and selectivity, and avoids the use of complicated/commercially unavailable organic ligands. Various primary amines and secondary amines have been successfully transformed into the corresponding formamides under mild conditions, and the formylation of primary diamines has also been achieved for the first time. The Fe catalyst 1 can be reused several times without appreciable loss of activity.
- Wu, Zhikang,Zhai, Yongyan,Zhao, Wenshu,Wei, Zheyu,Yu, Han,Han, Sheng,Wei, Yongge
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supporting information
p. 737 - 741
(2020/02/25)
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- A green route to polyurethanes: Oxidative carbonylation of industrially relevant aromatic diamines by CO2-based methyl formate
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The oxidative carbonylation of toluene-2,4-diamine (TDA) with methyl formate (MF), which can be produced from CO2, provides a possible route for the non-phosgene production of isocyanate precursors and enables a valuable utilization of the greenhouse gas. Extensive analysis of the product spectrum has provided detailed insight into the reaction network leading to the target product toluene-2,4-dicarbamate (TDC) and the most important side products. The most prominent one has been identified as methylene-bridged tetracarbamate 5, which is also an interesting precursor for applications in polyurethane chemistry. The side products are caused by three different reaction paths: N-formylation by MF, condensation with in situ formed formaldehyde, and N-methylation by in situ formed dimethyl carbonate (DMC). The influence of the catalyst on product distribution was evaluated for PdCl2/CuCl2 and a large number of heterogeneous Pd-catalysts. The oxidic support materials ZrO2, CeO2 and SiO2 were found to partially suppress the undesired side reactions leading to higher yields of TDC and tetracarbamate 5. The ratio of TDC to 5 was demonstrated to be affected significantly by the choice of the support. The synthetic protocol was extended to the synthesis of dicarbamates from 4,4′-methylenedianiline (MDA) and 2,4-diaminomesitylene (17). These results encourage further investigations into the design of selective catalysts for the production of isocyanate precursors from CO2 as a C1 source.
- Hussong, Christine,Langanke, Jens,Leitner, Walter
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supporting information
p. 8260 - 8270
(2020/12/31)
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- Co3O4 nanoparticles prepared by oxidative precipitation method: an efficient and reusable heterogeneous catalyst for N-formylation of amines
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Abstract: N-formylation of different amines was carried out with formic acid in the presence of the Co3O4 nanoparticles as an efficient, stable heterogeneous catalyst to give the corresponding formamides under solvent-free conditions. This method has advantages over the reported methods such as high yields, mild conditions, easy work-up and short reaction times. The catalyst was characterized by different techniques such as XRD, SEM and FT-IR spectroscopy. Graphical Abstract: [Figure not available: see fulltext.]
- Marjani, Ahmad Poursattar,Hosseini, Seyed Ali,Shokri, Zahra,Maleki, Nasim
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p. 413 - 422
(2017/01/14)
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- PROCESS FOR THE PREPARATION OF AROMATIC FORMAMIDES
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The invention relates to a process for the preparation of formamides by reacting aromatic amines with a formic acid ester in the presence of a catalyst, wherein the catalyst is a phosphorus-containing acid or a Lewis-acidic metal salt.
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Page/Page column 4
(2012/10/08)
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