288608-09-3Relevant academic research and scientific papers
Catalytic applications of nano β-PbO in Paal-Knorr reaction
Pasha, Sk. Khadeer,Satyanarayana,Sivakumar,Chidambaram,Kennedy, L. John
, p. 891 - 894 (2011)
Several 2,5-dimethyl-N-substituted pyrroles were prepared by the condensation of different substituted anilines with 2,5-hexanedione using nano lead oxide as an efficient and recyclable catalyst. All the synthesized compounds are confirmed through IR, 1H NMR, 13C NMR and mass spectral data. Nano lead oxide β-PbO (P85) was prepared by dissolving lead acetate dihydrate in 1-propanol at a pH 9.0 under stirring at 85 °C. The structural study and surface morphology of the lead oxide (PbO) were characterized using X-ray diffraction (XRD), Scanning electron microscopy (SEM) and the functional groups of the PbO sample were investigated using infrared spectrophotometer.
Synthesis of enantiomerically pure dissymmetric 2,2′-disubstituted 9,9′-spirobifluorenes
Thiemann, Frank,Piehler, Torsten,Haase, Detlev,Saak, Wolfgang,Luetzen, Arne
, p. 1991 - 2001 (2005)
Racemic dissymmetric 2,2′-dihydroxy-9,9′-spirobifluorene was prepared and resolved by clathrate formation with (R,R)-(+)-2,3-dimethoxy-N,N, N′,N′-tetracyclohexylsuccindiamide, giving rise to both enantiomers in very good yields. The absolute stereochemistry of the resolved material could be assigned by an X-ray structure analysis of single crystals of the clathrate. Enantiomerically pure diols could be transformed into the corresponding ditriflates, which were then used as starting materials in different cross-coupling procedures to provide a number of new enantiomerically pure spiro compounds bearing versatile functional groups suitable for further elaboration, as demonstrated by some examples. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
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.]
Copper-catalyzed and additive free decarboxylative trifluoromethylation of aromatic and heteroaromatic iodides
Johansen, Martin B.,Lindhardt, Anders T.
supporting information, p. 1417 - 1425 (2020/03/03)
A copper-catalyzed decarboxylative trifluoromethylation of (hetero)aromatic iodides has been developed. Importantly, this new copper-catalyzed reaction operates in the absence of any ligands and metal additives. The protocol shows good functional group tolerance and is compatible with heteroaromatic systems. The reaction proved scalable to a 15 mmol scale with increased yield. Finally, late-stage installation of the trifluoromethyl functionality afforded the N-trifluoroacetamide variant of the antidepressant agent, Prozac, demonstrating the applicability of the developed method.
A mild and efficient method for the synthesis of pyrroles using MIL-53(Al) as a catalyst under solvent-free sonication
Nguyen, Hai Truong,Thuy Nguyen, Linh Ho,Le Hoang Doan, Tan,Tran, Phuong Hoang
, p. 9093 - 9098 (2019/03/28)
A highly efficient method for the synthesis of pyrroles using MIL-53(Al) as a catalyst has been developed under solvent-free sonication. This reaction has a broad substrate scope and high yields were obtained within a short reaction time. Remarkably, no additional additives and volatile organic solvent are required for this method and the MIL-53(Al) could be recovered and reused several times without significant drop-off in catalytic activity.
New nano-Fe3O4-supported Lewis acidic ionic liquid as a highly effective and recyclable catalyst for the preparation of benzoxanthenes and pyrroles under solvent-free sonication
Nguyen, Hai Truong,Thi Le, Ngoc-Phuong,Nguyen Chau, Duy-Khiem,Tran, Phuong Hoang
, p. 35681 - 35688 (2018/10/31)
A novel magnetic nanomaterial-immobilized Lewis acidic ionic liquid was successfully synthesized by the covalent embedding of 3-(3-(trimethoxysilyl)propyl)-1H-imidazol-3-ium chlorozincate (ii) ionic liquid to the surface of Fe3O4 nanoparticles. The material was then characterized by FT-IR, SEM, TEM, TGA, ICP-OES, Raman, and EDS. Its performance as a new-generation Lewis acidic catalyst was also examined on the ultrasound-mediated synthesis of benzoxanthenes and pyrroles. Upon completion, the catalyst was simply recovered by an external magnet for multiple reuses without significant lessening of catalytic performance.
A green and efficient method for the synthesis of pyrroles using a deep eutectic solvent ([CholineCl][ZnCl2]3) under solvent-free sonication
Truong Nguyen, Hai,Nguyen Chau, Duy-Khiem,Tran, Phuong Hoang
, p. 12481 - 12489 (2017/11/06)
An efficient deep eutectic solvent-based synthesis of pyrroles under ultrasound irradiation has been developed to provide a significant improvement of the yield up to 99% in a short reaction time. The synthesis of pyrroles is highly atom-economical, producing water as the sole byproduct. In addition, [CholineCl][ZnCl2]3 is easily synthesized from commercially available choline chloride and zinc chloride via a cost-effective and environmentally benign pathway. The obtained [CholineCl][ZnCl2]3 has been characterized by FT-IR, 1H-NMR, 13C-NMR, HRMS (ESI), Raman, and TGA. Five new pyrroles are synthesized by the current method. Moreover, [CholineCl][ZnCl2]3 could be reused up to four times without significant loss of catalytic activity.
Greener Paal-Knorr Pyrrole Synthesis by Mechanical Activation
Akelis, Liudvikas,Rousseau, Jolanta,Juskenas, Robertas,Dodonova, Jelena,Rousseau, Cyril,Menuel, Stphane,Prevost, Dominique,Tumkeviius, Sigitas,Monflier, Eric,Hapiot, Frdric
, p. 31 - 35 (2016/01/20)
A straightforward and solventless synthesis of pyrroles was developed by using mechanochemical activation and a biosourced organic acid as the catalyst. Relative to traditional Paal-Knorr methodologies, various N-substituted pyrroles were obtained in very short reaction times. By reaction with unreactive diketones, desymmetrized aliphatic and aromatic compounds were also synthesized.
Synthesis of functionalized thiophene/phenyl co-oligomers by direct arylation of thiophenes
Osadnik, Andreas,Lützen, Arne
, p. 40 - 51 (2015/02/19)
π-Conjugated rod-like molecules have proven to be powerful candidates for the generation of well-defined nanostructures with interesting optical and optoelectrical properties. Their synthesis, however, turns out to be rather complex in some cases. Here, we have optimized the synthesis of oligomers consisting of thiophene and phenylene groups with three or four aromatic units using a direct arylation approach, which allows us to use cheap starting materials and to minimize the number of reaction steps considerably.
Organic synthesis in deep eutectic solvents: Paal-Knorr reactions
Handy, Scott,Lavender, Kevin
supporting information, p. 4377 - 4379 (2013/07/26)
Deep eutectic solvents (the combination of either urea or glycerol with choline chloride) are effective solvents/catalysts for Paal-Knorr reactions to form pyrroles of furans. The reaction conditions are quite mild and do not require the addition of an additional Bronsted or Lewis acid catalyst. Given the inexpensive, non-toxic, and recyclable nature of the DES, these reaction conditions are simple and highly environmentally friendly.
