1805-65-8Relevant academic research and scientific papers
An iron(iii)-catalyzed dehydrogenative cross-coupling reaction of indoles with benzylamines to prepare 3-aminoindole derivatives
Chen, Wei-Li,Li, Kun,Liang, Cui,Liang, Wang-Fu,Liao, Wei-Cong,Mo, Dong-Liang,Qiu, Pei-Wen,Su, Gui-Fa
supporting information, p. 9610 - 9616 (2021/12/09)
We report a green cascade approach to prepare a variety of 3-aminoindole derivatives in good to excellent yields through an iron(iii)-catalyzed dehydrogenative cross-coupling reaction of 2-arylindoles and primary benzylamines under mild reaction conditions. Mechanistic studies show that a cascade reaction involves a tert-butyl nitrite (TBN)-mediated nitrosation of 2-substituted indoles and a 1,5-hydrogen shift to afford indolenine oximes, sequential iron(iii)-catalyzed condensation and a 1,5-hydrogen shift over four steps in a one-pot reaction. The reaction shows a broad substrate scope of indoles and benzylamines and tolerates a wide range of functional groups. Moreover, the reaction is easily performed at the gram scale without producing waste after the reaction is completed. The 3-aminoindole product is purified by simple extraction, washing, and recrystallization without flash column chromatography. A double imine ligand containing the 3-aminoindole unit is facile to obtain in a 52% yield in one step. The present method highlights readily available starting materials, a simple purification procedure, and the usage of cheap, nontoxic, and environmentally benign iron(iii) catalysts. This journal is
Modular counter-Fischer?indole synthesis through radical-enolate coupling
Chung, Hyunho,Kim, Jeongyun,Gonzalez-Montiel, Gisela A.,Cheong, Paul Ha-Yeon,Lee, Hong Geun
supporting information, p. 1096 - 1102 (2021/01/26)
A single-electron transfer mediated modular indole formation reaction from a 2-iodoaniline derivative and a ketone has been developed. This transition-metal-free reaction shows a broad substrate scope and unconventional regioselectivity trends. Moreover, important functional groups for further transformation are tolerated under the reaction conditions. Density functional theory studies reveal that the reaction proceeds by metal coordination, which converts a disfavored 5-endo-trig cyclization to an accessible 7-endo-trig process.
DFT-Guided Phosphoric-Acid-Catalyzed Atroposelective Arene Functionalization of Nitrosonaphthalene
Ding, Wei-Yi,Yu, Peiyuan,An, Qian-Jin,Bay, Katherine L.,Xiang, Shao-Hua,Li, Shaoyu,Chen, Ying,Houk,Tan, Bin
, p. 2046 - 2059 (2020/07/13)
Guided by computational design, Tan and colleagues disclose a chiral phosphoric-acid-catalyzed asymmetric functionalization of naphthalenes with nitroso as the activating and directing group. This nucleophilic aromatic substitution reaction allows divergent access to two types of axially chiral arylindole frameworks with wide substrate generality under excellent enantiocontrol and, more importantly, offers a facile approach to the privileged NOBIN (2-amino-2′-hydroxy-1,1′-binaphthyl) structures. DFT calculations illustrate the plausible reaction pathway and provide additional insights into the origins of enantioselectivity.Functionalization of arenes represents the most efficient approach for constructing a core backbone of important aryl compounds. Compared with the well-developed electrophilic aromatic substitution and transition-metal-catalyzed C–H activation, nucleophilic aromatic substitution remains challenging because of the lack of a convenient route for rapid conversion of the σH adduct to other stable and versatile intermediates in situ. Guided by computational design, we were able to realize asymmetric nucleophilic aromatic substitution by introducing a nitroso group on naphthalene via chiral phosphoric acid catalysis. This strategy enables efficient construction of atropisomeric indole-naphthalenes and indole-anilines with excellent stereocontrol. Density functional theory (DFT) calculations provide further insights into the origins of enantioselectivity and the reaction mechanisms. The successful application in the synthesis of NOBINs (2-amino-2′-hydroxy-1,1′-binaphthyl) extends the utility of this strategy.Highly efficient conversion of inexpensive and readily available arene materials into high-value-added chiral molecules is of great importance in modern synthetic chemistry given the enormous potential of such structures in functional materials, pharmaceuticals, and other relevant chemical industries. Organocatalytic nucleophilic aromatic substitution enabled by an azo group offers an effective approach to enantioselective functionalization of naphthalene C–H bonds featuring an intramolecular oxidation of an unstabilized σH adduct. Premised on density functional theory (DFT) calculations, nitroso has emerged as another promising activating and oxidative group, whose synthetic potential is substantiated in the atroposelective synthesis of several groups of representative biaryl atropisomers processed by a chiral phosphoric acid catalyst. The success of this reaction explicitly exemplifies the ability of computational tools to streamline organic synthesis with intensified robustness in the disclosed strategy.
α-Imino Iridium Carbenes from Imidoyl Sulfoxonium Ylides: Application in the One-Step Synthesis of Indoles
Burtoloso, Antonio C. B.,Caiuby, Clarice A. D.,De Jesus, Matheus P.
, p. 7433 - 7445 (2020/06/27)
Imidoyl sulfoxonium ylides are presented for the first time as potential precursors to generate α-imino metal-carbene intermediates and applied in direct C-H functionalization reactions catalyzed by [Ir(cod)Cl]2 (4 mol %) to provide 2-substituted indoles (up to 70% yield) in just one step. This class of sulfur ylide is successfully obtained from imidoyl chloride and dimethylsulfoxonium methylide (23 new examples in 45-85% yield) or by imino group formation from the corresponding β-keto sulfoxonium ylides and anilines in the presence of TiCl4 as a Lewis acid (9 examples in 33-94% yield).
Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C-H Functionalization of Indoles
Guillemard, Lucas,Jacob, Nicolas,Wencel-Delord, Joanna
supporting information, p. 574 - 580 (2020/02/13)
Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C-H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.
Selective Inhibition of Histone Deacetylase 10: Hydrogen Bonding to the Gatekeeper Residue is Implicated
Géraldy, Magalie,Morgen, Michael,Sehr, Peter,Steimbach, Raphael R.,Moi, Davide,Ridinger, Johannes,Oehme, Ina,Witt, Olaf,Malz, Mona,Nogueira, Mauro S.,Koch, Oliver,Gunkel, Nikolas,Miller, Aubry K.
, p. 4426 - 4443 (2019/05/17)
The discovery of isozyme-selective histone deacetylase (HDAC) inhibitors is critical for understanding the biological functions of individual HDACs and for validating HDACs as drug targets. The isozyme HDAC10 contributes to chemotherapy resistance and has
Palladium-Catalyzed C–C Ring Closure in α-Chloromethylimines: Synthesis of 1H-Indoles
Bellezza, Delia,Noverges, Bárbara,Fasano, Francesco,Sarmiento, Jeymy T.,Medio-Simón, Mercedes,Asensio, Gregorio
, p. 1229 - 1235 (2019/01/04)
The C-C ring closure of α-chloromethyl alkyl or aryl N-aryl imines catalyzed with 1 to 10 % Pd(OAc)2/P(p-tolyl)3 afford efficiently 2-aryl- and 2-alkyl-1H-indoles. The heterocyclization reaction involves the initial formation of [2-(arylimino)ethyl]palladium(II) chloride complexes with subsequent C-H activation of the aromatic amine ring. Readily or commercially available α-chloromethyl-aryl or -alkyl ketones are used as the precursors. Functionalized indoles at the benzene ring are obtained when the imines are derived from substituted anilines.
Cp*IrIII-Catalyzed [3+2] Annulations of N-Aryl-2-aminopyrimidines with Sulfoxonium Ylides to Access 2-Alkyl Indoles Through C–H Bond Activation
Luo, Yi,Guo, Lingmei,Yu, Xinling,Ding, Haosheng,Wang, Huijing,Wu, Yong
, p. 3203 - 3207 (2019/06/08)
The iridium-catalyzed aromatic C–H alkylation followed by intramolecular annulation reactions between N-aryl-2-aminopyridines and sulfoxonium ylides for the synthesis of 2-alkyl indoles is described. This highly efficient and step-economical cyclization r
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.
Synthetic method of 2-substituted indoles compounds
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Paragraph 0010; 0035-0037; 0041; 0043; 0055, (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.
