2405-02-9Relevant articles and documents
An expeditious and highly efficient synthesis of substituted pyrroles using a low melting deep eutectic mixture
Alvi, Shakeel,Ali, Rashid
, p. 9732 - 9745 (2021/12/01)
An expeditious green method for the synthesis of diverse valued substituted pyrroles through a Paal-Knorr condensation reaction, using a variety of amines and 2,5-hexanedione/2,5-dimethoxytetrahydrofuran in the presence of a low melting mixture ofN,N’-dimethylurea andL-(+)-tartaric acid (which acts as a dual catalyst/solvent system), has fruitfully been revealed. Herein, we have disclosed the applicability of this simple yet effective strategy for the generation of mono- and dipyrroles in good to excellent yields. Moreover,C3-symmetric tripyrrolo-truxene derivatives have also been assembled by means of cyclotrimerization, Paal-Knorr and Clauson-Kaas reactions as crucial steps. Interestingly, the melting mixture was recovered and reused with only a gradual decrease in the catalytic activity (over four cycles) without any significant drop in the yield of the product. This particular methodology is simple, rapid, environmental friendly, and high yielding for the generation of a variety of pyrroles. To the best of our knowledge, the present work reveals the fastest greener method reported up to this date for the construction of substituted pyrroles by utilizing the Paal-Knorr synthetic protocol, achieving impressive yields under operationally simple reaction conditions without involving any precarious/dangerous catalysts or unsafe volatile organic solvents.
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 two distinct pyrrole moiety-containing arenes from nitroanilines using Paal-Knorr followed by an indium-mediated reaction
Kim, Byeong Hyo,Bae, Seolhee,Go, Ahra,Lee, Hyunseung,Gong, Cheoloh,Lee, Byung Min
, p. 265 - 276 (2015/12/30)
Synthesis of arenes substituted with two differently substituted-pyrrole moieties was investigated. A Paal-Knorr condensation reaction of nitroanilines with 1,4-diketone to nitrophenyl-1H-pyrroles followed by an indium-mediated reduction-triggered coupling reaction with another kind of 1,4-diketone resulted in two distinct pyrrole-containing arenes, variously substituted 1-((1H-pyrrol-1-yl)phenyl)-1H-pyrroles, in reasonable yield.
Paal-knorr pyrrole synthesis in water
Akbaslar, Dilek,Demirkol, Onur,Giray, Sultan
supporting information, p. 1323 - 1332 (2014/04/17)
Water was a suitable medium for Paal-Knorr pyrrole cyclocondensation. Hexa-2,5-dione was reacted with several aliphatic and aromatic primary amines, affording N-substituted 2,5-dimethyl pyrrole derivatives in good to excellent yields. An efficient, green method using water either as environmentally friendly solvent or catalyst was presented.
Nanomagnetically modified sulfuric acid (γ-Fe2O 3@SiO2-OSO3H): An efficient, fast, and reusable catalyst for greener Paal-Knorr pyrrole synthesis
Cheraghi, Samaneh,Saberi, Dariush,Heydari, Akbar
, p. 1339 - 1343 (2014/07/21)
Paal-Knorr pyrrole synthesis was performed in the presence of superparamagnetic nanoparticles of modified sulfuric acid (γ-Fe 2O3@SiO2-OSO3H) as an efficient and magnetically separable catalyst. Recovery of the catalyst was simple using a magnet, allowing its reuse without significant loss of its catalytic activity (over five cycles).
Sulfamic acid heterogenized on functionalized magnetic Fe3O4 nanoparticles with diaminoglyoxime as a green, efficient and reusable catalyst for one-pot synthesis of substituted pyrroles in aqueous phase
Veisi, Hojat,Mohammadi, Pourya,Gholami, Javad
, p. 868 - 873 (2015/02/19)
Surface functionalization of magnetic nanoparticles is an elegant way to bridge the gap between heterogeneous and homogeneous catalysis. We have conveniently loaded sulfonic acid groups on amino-functionalized Fe3O4 nanoparticles affording sulfamic acid-functionalized magnetic Fe3O4 nanoparticles (MNPs/DAG-SO3H) as an active and stable magnetically separable acidic nanocatalyst, which was characterized using X-ray diffraction, Fourier transform infrared and energy-dispersive X-ray spectroscopies, scanning and transmission electron microscopies, vibrating sample magnetometry and elemental analysis. The catalytic activity of MNPs/DAG-SO3H was probed through one-pot synthesis of N-substituted pyrroles from γ-diketones and primary amines in aqueous phase at room temperature. The heterogeneous catalyst could be recovered easily by applying an external magnet device and reused many times without significant loss of its catalytic activity.
An efficient and green procedure for synthesis of pyrrole derivatives by Paal-Knorr condensation using sodium dodecyl sulfate in aqueous micellar
Veisi, Hojat,Azadbakht, Reza,Ezadifar, Mehdi,Hemmati, Saba
, p. E241-E246 (2013/06/04)
A simple, economical, and green approach to the synthesis of N-substituted pyrroles using sodium dodecyl sulfate as surfactant in water is described. The experiment protocol features simple operations, and the products are isolated in high to excellent yields (60-98%).
Synthesis, structural and biochemical activity studies of symmetrical and unsymmetrical pyrroles and their mononuclear Cu(II), Ni(II) and Co(II) complexes
Senses,Karabocek,Karabocek,Ekmekcioglu
experimental part, p. 3797 - 3801 (2012/09/08)
Monomeric copper(II), nickel(II) and Co(II) complexes of 2-(2,5-dimethyl-1H-pyrrol-1-yl)aniline, (dmpyph) and 1,1'-(1,2-phenylene)-bis(2, 5-dimethyl-1H-pyrrole) (tmpyph) were prepared and characterized by elemental analyses, magnetic moments, 1
Silica sulfuric acid (SSA) as a solid acid heterogeneous catalyst for one-pot synthesis of substituted pyrroles under solvent-free conditions at room temperature
Veisi, Hojat
scheme or table, p. 2109 - 2114 (2010/06/14)
A variety of N-substituted pyrroles have been synthesized by reacting γ-diketones with amines, diamines or triamine in the presence of silica sulfuric acid (SSA) at room temperature under solvent-free conditions. The experiment protocol features simple operations, and the products are isolated in high to excellent yields (70-98%).