- Utilization of caffeine carbon supported cobalt catalyst in the tandem synthesis of pyrroles from nitroarenes and alkenyl diols
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Employing bio-waste caffeine carbon-supported heterogeneous cobalt catalyst, synthesis of various substituted pyrrole derivatives is reported. In this methodology, pyrroles were synthesized through coupling between nitroarenes and alkenyl diols in a tandem manner. Among all the heterogeneous catalysts Co(OAc)2-CC-800 displayed the highest catalytic activity. Preparative scale synthesis of pyrroles and synthesis of anti-tubercular agent 5-(4-(1H-pyrrol-1-yl)phenyl)-1,3,4-oxadiazole-2-thiol revealed the practical applicability of this protocol. Several kinetic experiments and Hammett studies were conducted to understand the probable mechanism and electronic effects on this transformation.
- Panja, Dibyajyoti,Sau, Anirban,Balasubramaniam, Bhuvaneshwari,Dhara, Partha,Gupta, Raju K.,Kundu, Sabuj
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p. 244 - 254
(2021/09/07)
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- Solvent Free Synthesis of N-Substituted Pyrrole Derivatives Catalyzed by Silica Sulfuric Acid
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Sulfuric acid immobilized on silica gel is used as an efficient catalyst in the synthesis of N-substituted pyrrole derivatives by the Clauson–Kaas pyrrole synthesis. The solvent free reaction mixture is stirred by grinding. Within very short reaction time the process leads to the corresponding products without any decomposition recorded.
- Khammas,Yolacan,Aydogan
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p. 2680 - 2683
(2019/04/04)
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- Copper(I) Oxide/N,N′-Bis[(2-furyl)methyl]oxalamide-Catalyzed Coupling of (Hetero)aryl Halides and Nitrogen Heterocycles at Low Catalytic Loading
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An easily prepared oxalic diamide is a powerful ligand for the copper-catalyzed coupling of aryl halides with nitrogen heterocycles. Only 1–2 mol% each of copper(I) oxide and N,N′-bis[(2-furyl)methyl]oxalamide (BFMO) are needed to form N-arylation products under mild conditions. More than 10 different types of nitrogen heterocycles are compatible with these conditions, thereby giving the corresponding N-arylation products. (Figure presented.).
- Pawar, Govind Goroba,Wu, Haibo,De, Subhadip,Ma, Dawei
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supporting information
p. 1631 - 1636
(2017/05/22)
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- Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium-zinc base and regioselectivity-computed CH acidity relationship
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The synthesis of N-arylated pyrroles and indoles is documented, as well as their functionalization by deprotonative metallation using the base in situ prepared from LiTMP and ZnCl2·TMEDA (1/3 equiv). With N-phenylpyrrole and -indole, the reactions were carried out in hexane containing TMEDA which regioselectively afforded the 2-iodo derivatives after subsequent iodolysis. With pyrroles and indoles bearing N-substituents such as 2-thienyl, 3-pyridyl, 4-methoxyphenyl and 4-bromophenyl, the reactions all took place on the substituent, at the position either adjacent to the heteroatom (S, N) or ortho to the heteroatom-containing substituent (OMe, Br). The CH acidities of the substrates were determined in THF solution using the DFT B3LYP method in order to rationalize the experimental results.
- Messaoud, Mohamed Yacine Ameur,Bentabed-Ababsa, Ghenia,Hedidi, Madani,Derdour, A?cha,Chevallier, Floris,Halauko, Yury S.,Ivashkevich, Oleg A.,Matulis, Vadim E.,Picot, Laurent,Thiéry, Valérie,Roisnel, Thierry,Dorcet, Vincent,Mongin, Florence
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supporting information
p. 1475 - 1485
(2016/04/19)
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- Ligand-free Cu2O-catalyzed cross coupling of nitrogen heterocycles with iodopyridines
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A practical and efficient strategy has been developed for the cross coupling of nitrogen heterocycles with halopyridines using ligand-free Cu 2O as catalyst and Cs2CO3 as the base. The protocol is applicable to a series of highly functionalised heterocycles, such as 7-azaindole, indazole, indole, imidazole, pyrrole and pyrazole, affording the N-heteroaryl derivatives in high yields (up to 96%).
- Teo, Yong-Chua,Yong, Fui-Fong,Sim, Shirlyn
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p. 7279 - 7284
(2013/08/23)
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- Microwave-assisted solvent- and ligand-free copper-catalysed cross-coupling between halopyridines and nitrogen nucleophiles
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N-Heteroarylated products are obtained in good yields by microwave-assisted solvent- and ligand-free copper-catalysed amination of halopyridines with nitrogen nucleophiles.
- Liu, Zhen-Jiang,Vors, Jean-Pierre,Gesing, Ernst R. F.,Bolm, Carsten
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supporting information; experimental part
p. 42 - 45
(2011/03/19)
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- Preparation of N-arylpiperazines and other N-aryl compounds from aryl bromides as scaffolds of bioactive compounds
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Aryl bromides are coupled with N-compounds to give the corresponding arylamines in the presence of a palladium catalyst, a suitable ligand, and a weak base. The catalysts perform well for a large number of different starting material combinations at 100-150 °C with drops of toluene or without solvent, and with low catalyst levels (0.12 mol % Pd). The low catalyst amount makes the process environment friendly.
- Romero,Harrak,Basset,Ginet,Constans,Pujol
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p. 9010 - 9016
(2007/10/03)
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