83-24-9Relevant articles and documents
Multimolecular self-organization of acetylene and arylamines into 1-aryl-3-ethyl-4-vinylpyrroles in the KOBut/DMSO system
Ivanova, Elena V.,Schmidt, Elena Yu.,Semenova, Nadezhda V.,Trofimov, Boris A.,Ushakov, Igor A.
, p. 315 - 317 (2020)
A new superbase-driven self-organization of four molecules of acetylene with one molecule of arylamine to 1-aryl-3ethyl-4-vinylpyrroles in the KOBut/DMSO system has been discovered. The process includes four acts of nucleophilic addition to acetylene followed by intramolecular cyclization of intermediate N,N-bis(1,3-dienyl)-N-arylamine.
Ultrasound-Promoted One-Pot Synthesis of Mono- or Bis-Substituted Organylselanyl Pyrroles
Peglow, Thiago J.,Da Costa, Gabriel P.,Duarte, Luis Fernando B.,Silva, Márcio S.,Barcellos, Thiago,Perin, Gelson,Alves, Diego
, p. 5471 - 5482 (2019)
A simple method for the direct mono- and bis-organylselenylation of N-substituted pyrroles through a multicomponent reaction promoted by ultrasonic radiation was described. These sonochemical promoted reactions were performed between different primary amines, 2,5-hexanedione and dialkyl, diheteroaryl, or diaryl diselenides, using catalytic amounts of copper iodide. Depending on the amount of copper iodide and diorganyl diselenide used in the reactions, mono- or bis-organylselenylation products were efficiently synthesized in high yields.
Magnetic solid sulfonic acid-enabled direct catalytic production of biomass-derived N-substituted pyrroles
Li, Hu,Liu, Yixuan,Wang, Keping,Wu, Mei,Yang, Ying
, p. 5312 - 5320 (2022/04/07)
Five-membered nitrogen heterocyclic pyrroles have extremely high physiological activity and are widely used in medicine, agriculture, materials chemistry, industry, and supramolecular chemistry. Developing a mild and eco-friendly way to synthesize functionalized pyrroles from biologically derived materials is desirable. In this study, biomass-derived 2,5-dimethylfuran can react with a series of aromatic amines to synthesize 2,5-dimethyl-N-arylpyrroles through acid-enabled ring-opening and Paal-Knorr condensation in one pot. Among the tested acid catalytic materials, a new magnetic biocarbon-based sulfonic acid solid catalyst (WK-SO3H) showed excellent catalytic performance in the synthesis of N-substituted pyrroles (up to ca. 90% yield) and was easy to separate and recover by an external magnetic field. The ring-opening of furan proved to be the rate-determining step of the above one-pot multi-step conversion process, and 2,5-hexanedione is a key intermediate for the cascade reaction, while the addition of water could significantly enhance the above-mentioned ring-opening reaction. Furthermore, multiple characterization methods (e.g., FT-IR, TGA, XRD, NH3-TPD, and XPS) confirmed that WK-SO3H has good stability in the aqueous reaction system.
A convenient approach for the synthesis of substituted pyrroles by using phosphoric acid as a catalyst and their photophysical properties
Ai, Liankun,Ibrahim, Yusuf Ajibola,Li, Baolin,Li, Jiahui
, (2021/12/21)
Twenty-three new pyrrole compounds aside from six knowns, including the synthetically challenging tetra- and penta-substituted pyrroles from the corresponding 1,4-dicarbonyl through Paal-Knorr synthesis in the presence of 5% phosphoric acid as the catalyst. Our method is noteworthy for cheap catalyst, uncomplicated experimental setup under air atmosphere, scalability, and excellent yields. The fluorescence of some selected pyrroles was investigated in dilute solution, and we found that all novel pyrroles emit strong blue fluorescences with considerable Stokes shifts.
A Highly Dispersed Copper Nanoparticles Catalyst with a Large Number of Weak Acid Centers for Efficiently Synthesizing the High Value-Added 3-Methylindole by Aniline and Biomass-Derived Glycerin
Sun, Pinghui,Lin, Shuyi,Guo, Huimei,Su, Jianhui,Shi, Lei
, p. 463 - 477 (2020/07/16)
Abstract: An excellent catalyst with a large number of weak acid centers and highly dispersed copper nanoparticles embedded in mesoporous SBA-15 carrier was successfully constructed for the purpose of efficient conversion of aniline with biomass-derived glycerin to the high value-added 3-methylindole, in which the catalyst of Cu/SBA-15 was modified with Al2O3, La2O3 and CoO in sequence. The modified carrier and the copper-based catalysts were studied by scanning electron microscopy and energy-dispersive X-ray (SEM–EDX) spectroscopy, nitrogen physical adsorption, ammonia temperature programmed desorption (NH3-TPD), hydrogen temperature programmed reduction (H2-TPR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric and differential thermal analysis (TG–DTA) and inductively coupled plasma (ICP) emission spectroscopy. The research found that the Cu/CoO/La2O3/Al2O3/SBA-15 catalyst exhibited a very good catalytic performance with 3-methylindole yield up to 73.3% and selectivity reaching 86.4%. Besides, only a 3.9% yield decreased after the catalyst was circulated seven times. The characterizations revealed that Al2O3 could enhance the polarity of the carrier, thereby the interaction between the active component and the composite carrier was strengthened and the dispersion of copper was increased significantly. Adding La2O3 to Cu/SBA-15-Al2O3 could weaken the acidity and inhibit the formation of carbon deposits. CoO promoter could increase the number of weak acid centers, which was conducive to a good dispersion of active component and the high selectivity of 3-methylindole. Furthermore, the reaction pathway of gas-phase synthesis of 3-methylindole from glycerin and aniline on Cu/CoO/La2O3/Al2O3/SBA-15 was explored. Graphic Abstract: [Figure not available: see fulltext.]
Preparation method of biomass-based 2, 5-dimethyl-N-substituted pyrrole derivative
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Paragraph 0023-0048, (2021/07/14)
The invention discloses a preparation method of a biomass-based 2, 5-dimethyl-N-substituted pyrrole derivative. The method comprises the following steps: adding 2, 5-dimethylfuran, an amine compound, a catalyst, distilled water and 2mL of solvent into a reaction kettle, and heating the reaction kettle in an oil bath pan; and obtaining the 2, 5-dimethyl-N-substituted pyrrole derivative after the temperature is 110-170 DEG C, the use amount of distilled water is 0-250 [mu] L, the use amount of the catalyst is 5-10 wt%, and the reaction time is 1-3 h. The method overcomes the defects of high cost and difficulty in separation and recovery of the existing catalyst or catalyst system.
One-pot synthesis of cyclohexylamine and: N -aryl pyrroles via hydrogenation of nitroarenes over the Pd0.5Ru0.5-PVP catalyst
Chaudhari, Chandan,Sato, Katsutoshi,Ikeda, Yasuyuki,Terada, Kenji,Abe, Naoya,Nagaoka, Katsutoshi
supporting information, p. 9743 - 9746 (2021/06/15)
The direct synthesis of cyclohexylamine via the hydrogenation of nitrobenzene over monometallic (Pd, Ru or Rh) and bimetallic (PdxRu1-x) catalysts was studied. The Pd0.5Ru0.5-PVP catalyst was the most effective catalyst for this reaction. The catalyst can be reused and applied for the synthesis of N-aryl pyrroles and quinoxalines from nitrobenzenes.
Crystalline salicylic acid as an efficient catalyst for ultrafast Paal–Knorr pyrrole synthesis under microwave induction
Aghapoor, Kioumars,Mohsenzadeh, Farshid,Darabi, Hossein Reza,Sayahi, Hani
, (2021/04/19)
Abstract: In this study, the viability of a wide range of crystalline aromatic and aliphatic carboxylic acids as organocatalysts has been investigated for solvent-free Paal–Knorr pyrrole synthesis under microwave activation. Among these potential catalysts, crystalline salicylic acid proved to be a remarkable catalyst because its efficiency remained high even under low microwave power irradiation or a shorter reaction time for the model reaction. The outstanding catalytic activity of salicylic acid allowed the Paal–Knorr cyclocondensation with a turnover frequency up to 1472?h?1 which is unique in the context of a metal-free homogeneous catalysis. The attractive feature of this organocatalyst is its assistance in ultrafast pyrrole synthesis with no risk of metal contamination. Graphic abstract: [Figure not available: see fulltext.] Synopsis: A green and expeditious protocol for the synthesis of 2,5-dimethylpyrroles via combination of salicylic acid as catalyst (in its solid state) and microwaves has been introduced.
Facile fabrication of porous magnetic covalent organic frameworks as robust platform for multicomponent reaction
Azizi, Najmedin,Heidarzadeh, Fatemeh,Farzaneh, Fezeh
, (2021/07/26)
The design of cheap yet efficient nanoporous magnetic catalysts for the environmentally benign process's widespread application is an extremely attractive, challenging chemical research field. A novel porous magnetic covalent organic framework was prepared by the condensation reaction of melamine and terephthaladehyde on the surface of 3,4-dihydroxybenzaldehyde coated magnetic Fe3O4 nanoparticles COF@Fe3O4 under hydrothermal conditions for the first time. The high surface area magnetic COF could exhibit superior catalytic activity for sustainable synthesis of trisubstituted and tetrasubstituted imidazoles and pyrroles in good to excellent yields in PEG as solvent under environmentally friendly, ambient conditions and making the overall process economical, efficient, and green. The retrievable catalyst in PEG is general and applicable to a broad substrate scope and functional group compatibility. The structure and morphology of the COF@Fe3O4 were characterized by FTIR, XRD, EDX, and SEM spectroscopy. The COF@Fe3O4 magnetic catalyst was recovered by an external magnet and used for several cycles without significant catalytic activity loss.
Amidosulfonic acid supported on graphitic carbon nitride: novel and straightforward catalyst for Paal–Knorr pyrrole reaction under mild conditions
Azhdari, Asieh,Azizi, Najmedin,Sanaeishoar, Haleh,Tahanpesar, Elham
, p. 625 - 634 (2021/05/12)
A novel heterogeneous acidic catalyst was prepared by in situ immobilization of amidosulfonic acid (NH2SO3H) on graphitic carbon nitride (g-C3N4) under hydrothermal conditions. The textural morphology of NH2SO3H/g-C3N4 nanocomposite was characterized via powder X-ray diffraction, FT-IR, TGA, EDX, and scanning electron microscopy. The spatial arrangement of the amidosulfonic acid on the surface of g-C3N4 leads to the construction of a unique solid acid structure, resulting in a substantial enhancement of catalytic activity toward a high efficient preparation of pyrroles by Paal–Knorr reaction. The reactions undergo completion readily with good to excellent yields, with simple purification in an environmentally friendly manner. The NH2SO3H/g-C3N4 nanocomposite can be readily recycled, and no noteworthy reduction in the catalytic activity detected after four runs. Graphic abstract: [Figure not available: see fulltext.]
