1504-16-1Relevant articles and documents
Direct palladium-catalyzed C-3 arylation of indoles
Zhang, Zhiqiang,Hu, Zhizhi,Yu, Zhixiao,Lei, Peng,Chi, Haijun,Wang, Yue,He, Ren
, p. 2415 - 2419 (2007)
An efficient protocol for palladium-catalyzed direct C-3 arylation of indoles containing unprotected heterocyclic nitrogen atom has been developed.
A facile access to substituted indoles utilizing palladium catalyzed annulation under microwave enhanced conditions
Karuvalam, Ranjith P.,Haridas, Karickal R.,Sajith, Ayyiliath M.,Muralidharan, Arayambath
, p. 5126 - 5129 (2013)
A facile access to differently substituted indoles using palladium catalyzed annulation reactions under microwave enhanced conditions has been achieved. A highly active and efficient catalytic system PdCl 2/(A-taphos) for the synthesis of indole via palladium catalyzed ring annulation of ortho iodo anilines and aldehydes has been developed.
Mechanistic Study of Direct Arylation of Indole Using Differential Selectivity Measurements: Shedding Light on the Active Species and Revealing the Key Role of Electrophilic Substitution in the Catalytic Cycle
Kurokhtina, Anna A.,Larina, Elizaveta V.,Yarosh, Elena V.,Lagoda, Nadezhda A.,Schmidt, Alexander F.
, p. 2054 - 2063 (2018)
Differential selectivity of the direct arylation of indole with aryl halides under competing and noncompeting conditions with a varying set of reaction parameters was determined using phase trajectories. The results described herein allow for conclusions to be drawn regarding the character of active complexes (cationic, neutral, or anionic) as well as realization of the indole electrophilic substitution in the catalytic cycle using the ligand-free catalytic system.
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Isomura et al.
, p. 664 (1977)
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Development of Pd Supported Catalysts Using Thiol-Functionalized Mesoporous Silica Frameworks: Application to the Chemo- and Regioselective C-3 Arylation of Free-Indole
Renom Carrasco, Marc,Khodja, Walid,Demarcy, Clément,Veyre, Laurent,Camp, Clément,Thieuleux, Chloé
, p. 814 - 820 (2021)
We report here the development of Pd-supported catalysts for the selective C-3 arylation of free-indole using thiol-functionalized silica supports to anchor the palladium centers. The palladium (II) complex, Pd(OAc)2, was efficiently loaded into various thiol-functionalized mesostructured silicas at room temperature. These materials exhibit different contents of surface SH groups (0.3 to 1.8 SH/nm2) and various SH/Pd molar ratios from 6 to 65. It was found that the catalysts containing the most isolated surface SH groups (0.3 SH/nm2) and the highest loading of Pd were the most active, reaching 70 % of conversion, 1400 as turnover numbers and 100 % selectivity in the C-3 arylated product using only 0.05 mol % of Pd. However, a leaching of active Pd species (1.7 ppm) was detected. The best compromise was found for a specific solid containing isolated surface thiol groups (0.3 SH/nm2) and a very low loading of Pd (SH/Pd=65). It exhibited a high TON (608) with a very low Pd leaching of 0.5 ppm in the course of the catalytic reaction. These results thus illustrate that both surface SH sites isolation and concentration, as well as the SH/Pd molar ratio are key parameters to access high catalytic performances and very low leaching of metal during catalysis.
Efficient synthesis of N-methoxyindoles via alkylative cycloaddition of nitrosoarenes with alkynes
Penoni, Andrea,Palmisano, Giovanni,Broggini, Gianluigi,Kadowaki, Ayako,Nicholas, Kenneth M.
, p. 823 - 825 (2006)
N-Methoxyindoles are produced in moderate to excellent yields from the reaction between nitrosoarenes and alkynes in the presence of K 2CO3/(CH3)2SO4. Terminal alkynes with conjugating substituents af
Pd/β-cyclodextrin-catalyzed C-H functionalization in water: A greener approach to regioselective arylation of (NH)-indoles with aryl bromides
Duan, Xin Hong,Xu, Peng
supporting information, p. 19425 - 19431 (2021/11/09)
A greener and more practical strategy for the site-selective C-H arylation of (NH)-indoles via coupling of (hetero)aryl bromides was developed, in which β-cyclodextrin, acting as both a ligand for Na2PdCl4 and a host for indoles, enables the reactions to occur easily in water. The key advantage of this method is the ingenious merging of aqueous homogeneous catalysis and ligand mediation, leading to the highly regioselective formation of C3-arylindoles with a broad substrate scope and functional-group tolerance. Moreover, the regioselectivity can be switched from the C3 to the C2-position by varying the nature of the base without recourse to employing ArI as substrates.
Electro-Oxidative C-N Bond Formation through Azolation of Indole Derivatives: An Access to 3-Substituent-2-(Azol-1-yl)indoles
Zhou, Naifu,Zhao, Junhao,Sun, Chengbo,Lai, Yuqin,Ruan, Zhixiong,Feng, Pengju
, p. 16059 - 16067 (2021/10/01)
A practical protocol to synthesize 3-substituent-2-(azol-1-yl)indole derivatives has been developed via an electrochemical oxidative cross coupling process under mild conditions. This electro-oxidative C-N bond formation strategy tolerates a range of functional groups and is amenable to gram scale synthesis. Moreover, this method was applied to the late-stage functionalization of bioactive molecules.