66354-67-4Relevant academic research and scientific papers
One-Pot Asymmetric Oxidative Dearomatization of 2-Substituted Indoles by Merging Transition Metal Catalysis with Organocatalysis to Access C2-Tetrasubstituted Indolin-3-Ones
Zhao, Yong-Long,An, Jian-Xiong,Yang, Fen-Fen,Guan, Xiang,Fu, Xiao-Zhong,Li, Zong-Qin,Wang, Da-Peng,Zhou, Meng,Yang, Yuan-Yong,He, Bin
, p. 1277 - 1285 (2022/03/14)
A one-pot approach for the asymmetric synthesis of C2-tetrasubstituted indolin-3-ones from 2-substituted indoles was developed via merging transition metal catalysis with organocatalysis. This strategy involves two processes, including CuI catalyzed oxidative dearomatization of 2-substituted indoles using O2 as green oxidant, and followed by an proline-promoted asymmetric Mannich reaction with ketones or aldehydes. A series of C2-tetrasubstituted indolin-3-ones were obtained in 35–86% yields, 2:1->20:1 dr and 48–99% ee. Moreover, the synthetic 2-tetrasubstituted indolin-3-ones could be easily transformed into 1H-[1,3] oxazino [3,4-a]indol-5(3H)-ones via a [4+1] cyclization process. In addition, the synthetic compound 3 s show certain antibacterial activity against S. aureus ATCC25923 and multi-drug resistance bacterial strain of S. aureus (20151027077) and its MIC values up to 8 μg/mL and 16 μg/mL, respectively. (Figure presented.).
Regioselective mercury(I)/palladium(II)-catalyzed single-step approach for the synthesis of imines and 2-substituted indoles
Delgado, Francisco,Gutiérrez, Rsuini U.,Hernández-Montes, Mayra,Mendieta-Moctezuma, Aarón,Tamariz, Joaquín
, (2021/07/21)
An efficient synthesis of ketimines was achieved through a regioselective Hg(I)-catalyzed hydroamination of terminal acetylenes in the presence of anilines. The Pd(II)-catalyzed cycliza-tion of these imines into the 2-substituted indoles was satisfactorily carried out by a C-H acti-vation. In a single-step approach, a variety of 2-substituted indoles were also generated via a Hg(I)/Pd(II)-catalyzed, one-pot, two-step process, starting from anilines and terminal acetylenes. The arylacetylenes proved to be more effective than the alkyl derivatives.
Pd-Catalyzed Reductive Cyclization of Nitroarenes with CO2 as the CO Source
Guan, Xinyu,Zhu, Haoran,Zhao, Yingwei,Driver, Tom G.
, p. 57 - 60 (2019/12/11)
A reductive amination process that constructs indoles, carbazoles or benzimidazoles from nitroarenes – irrespective of their electronic or steric nature – was developed that uses CO2 as the source of CO. The process is robust, tolerating common gaseous components of flue gas (H2S, SO2, NO and H2O) without adversely affecting the reductive cyclization.
Iron-catalyzed reductive coupling of nitroarenes with olefins: Intermediate of iron-nitroso complex
Song, Heng,Yang, Zhuoyi,Tung, Chen-Ho,Wang, Wenguang
, p. 276 - 281 (2019/12/24)
Using a single half-sandwich iron(II) compound, CpFe(1,2-Ph2PC6H4S)(NCMe) (Cp- = C5Me5-, 1) as a catalyst, reductive coupling of nitroarenes with olefins has been achieved by a well-defined iron(II)/(EtO)3SiH system. Through either inter- or intramolecular reductive coupling, various branched amines and indole derivatives have been directly synthesized in one-pot. Mechanistic studies showed that the catalysis is initiated by activation of nitroarenes by the iron(II) catalyst with silane, generating iron-nitrosoarene intermediate for the C-N bond coupling.
Regioselective Synthesis of 2-Arylindoles via Palladium-Catalyzed Cyclization of Phenylglyoxal and 2-Anilinoacetophenones with Anilines
Benitez-Medina, G. Eliad,Ortiz-Soto, Sofía,Cabrera, Armando,Amézquita-Valencia, Manuel
, p. 3763 - 3770 (2019/06/24)
A versatile route has been developed for the synthesis of 2-arylindoles using a Pd-catalyzed tandem process. Under reductive conditions, different 2-arylindoles were synthesized from phenylglyoxal and aniline. This synthetic methodology involves a tandem reaction of four steps with high regioselectivity. Alternatively, 2-anilinoacetophenones intermediates also can be using to give access to the corresponding 2-arylindoles.
Synthetic method of 2-substituted indoles compounds
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Paragraph 0010; 0035-0037; 0040; 0043-0044, (2019/05/02)
The invention discloses a synthetic method of 2-substituted indoles compounds, and belongs to the organic synthesis field. 2-fluorotoluene compound shown in formula 1 and nitrile compound shown in formula 2 mix with an organic solvent in the presence of strong alkali and cesium salt additives, and react to synthesize the 2-substituted indoles compounds shown in formula 3. The synthesis method of 2-substituted indoles compounds is simple, economical and has wider applicability, is suitable for large-scale production, and has a very important influence on the synthesis of indoles compounds.
Synthesis of Indoles through Domino Reactions of 2-Fluorotoluenes and Nitriles
Mao, Jianyou,Wang, Zhiting,Xu, Xinyu,Liu, Guoqing,Jiang, Runsheng,Guan, Haixing,Zheng, Zhipeng,Walsh, Patrick J.
supporting information, p. 11033 - 11038 (2019/07/08)
Indoles are essential heterocycles in medicinal chemistry, and therefore, novel and efficient approaches to their synthesis are in high demand. Among indoles, 2-aryl indoles have been described as privileged scaffolds. Advanced herein is a straightforward, practical, and transition-metal-free assembly of 2-aryl indoles. Simply combining readily available 2-fluorotoluenes, nitriles, LiN(SiMe3)2, and CsF enables the generation of a diverse array of indoles (38 examples, 48–92 % yield). A range of substituents can be introduced into each position of the indole backbone (C4 to C7, and aryl groups at C2), providing handles for further elaboration.
An Efficient Route to Highly Substituted Indoles via Tetrahydroindol-4(5H)-one Intermediates Produced by Ring-Opening Cyclization of Spirocyclopropanes with Amines
Nambu, Hisanori,Hirota, Wataru,Fukumoto, Masahiro,Tamura, Takafumi,Yakura, Takayuki
supporting information, p. 16799 - 16805 (2017/09/12)
An efficient route to highly substituted indoles was developed. It included regioselective functionalization of tetrahydroindol-4(5H)-ones, prepared by ring-opening cyclization of cyclohexane-1,3-dione-2-spirocyclopropanes with primary amines, and subsequent oxidation. The 6-substituted indoles were synthesized from a readily available 5-substituted cyclohexane-1,3-dione-2-spirocyclopropane. The synthesis of 5- and 7-substituted indoles was achieved by regioselective electrophilic alkylation of tetrahydroindol-4(5H)-one, followed by oxidation. The 4-substituted indoles were synthesized by nucleophilic alkylation of the corresponding pyrrole derivative, which was prepared by partial oxidation of tetrahydroindol-4(5H)-one, and sequential oxidation. The synthesis of 4-substituted indoles was also accomplished by palladium-catalyzed coupling of 4-hydroxyindole-derived triflates. Furthermore, the synthesis of 4,5,6,7-tetrasubstituted indoles was achieved by using these regioselective alkylations.
Iron-Catalyzed Reductive Cyclization of o-Nitrostyrenes Using Phenylsilane as the Terminal Reductant
Shevlin, Michael,Guan, Xinyu,Driver, Tom G.
, p. 5518 - 5522 (2017/08/17)
Using microscale high-throughput experimentation, an efficient, earth-abundant iron phenanthroline complex was discovered to catalyze the reductive cyclization of ortho-nitrostyrenes into indoles via nitrosoarene reactive intermediates. This method requires only 1 mol % of Fe(OAc)2 and 1 mol % of 4,7-(MeO)2phen and uses phenylsilane as a convenient terminal reductant. The scope and limitations of the method were illustrated with 21 examples, and an investigation into the kinetics of the reaction revealed first-order behavior in catalyst and silane and zero-order behavior with respect to nitrostyrene.
Palladium-catalyzed direct C2-arylation of free (N–H) indoles via norbornene-mediated regioselective C–H activation
Gao, Yadong,Zhu, Wangying,Yin, Long,Dong, Bo,Fu, Jingjing,Ye, Zhiwen,Xue, Fengtian,Jiang, Chao
supporting information, p. 2213 - 2216 (2017/05/16)
A palladium-catalyzed direct C2-arylation reaction of free (N–H) indoles has been developed. This reaction relies on a norbornene-mediated C–H activation process on the indole ring, which features high regioselectivity and excellent functional group tolerance.
