23746-76-1Relevant 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.).
Copper-Catalyzed Enantioselective C-H Arylation between 2-Arylindoles and Hypervalent Iodine Reagents
Liang, Hao,Zhu, Guoxun,Pu, Xiaoyun,Qiu, Liqin
supporting information, p. 9246 - 9250 (2021/12/06)
The copper-catalyzed enantioselective C-H arylation between 2-arylindoles and hypervalent iodine reagents has been successfully developed, which provides a convenient and economical route to the highly atroposelective synthesis of axially chiral indole de
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.
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.
Aniline-initiated and Br?nsted acid-catalyzed one-pot reaction toward 2-aryl-3-sulfenylindoles by using α-aminocarbonyl compounds and primary amines with RSSR
Chen, De,Cheng, Chaozhihui,Deng, Wei,Guan, Wenjian,Liu, Yuxuan,Luo, Yongyue,Xiang, Jiannan,Zhang, Jiajia
, (2020/12/01)
A highly novel method of direct synthesis of 2-aryl-3-sulfenylindoles in moderate to good yields was developed via one-pot tandem reaction of readily available α-aminocarbonyl compounds and catalytic amount of benzenamines with RSSR.
Acid-catalyzed cleavage of C-C bonds enables atropaldehyde acetals as masked C2 electrophiles for organic synthesis
Chen, Shaomin,Gu, Yanlong,Li, Minghao
, p. 10431 - 10434 (2021/10/12)
Acid-catalyzed tandem reactions of atropaldehyde acetals were established for the synthesis of three important molecules, 2,2-disubstituted indolin-3-ones, naphthofurans and stilbenes. The synthesis was realized using novel reaction cascades, which involved the same two initial steps: (i) SN2′ substitution, in which the atropaldehyde acted as an electrophile; and (ii) oxidative cleavage of the carbon-carbon bond of the generated phenylacetaldehyde-type products. Compared with literature methods, the present protocol not only avoided the use of expensive noble metal catalysts, but also enabled a simple operation.
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
, 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
B(C6F5)3-Catalyzed Electron Donor-Acceptor Complex-Mediated Aerobic Sulfenylation of Indoles under Visible-Light Conditions
Yuan, Wenkai,Huang, Jie,Xu, Xin,Wang, Long,Tang, Xiang-Ying
supporting information, p. 7139 - 7143 (2021/09/14)
An efficient B(C6F5)3-catalyzed aerobic oxidative C-S cross-coupling reaction of thiophenol with indoles was developed, affording a wide range of diaryl sulfides in good yields. An electron donor-acceptor complex between B(C6F5)3 and indoles was formed, facilitating the photoinduced single-electron transfer (SET) from indole substrates to the B(C6F5)3 catalyst. This protocol demonstrates a new reaction model using B(C6F5)3 as a single-electron oxidant.
Iminyl-radicals by electrochemical decarboxylation of α-imino-oxy acids: construction of indole-fused polycyclics
Wan, Jin-Lin,Cui, Jian-Feng,Zhong, Wei-Qiang,Huang, Jing-Mei
supporting information, p. 10242 - 10245 (2021/10/12)
Iminyl radicals are reactive intermediates that can be used for the construction of various valuable heterocycles. Herein, the electrochemical decarboxylation of α-imino-oxy acids for the generation of iminyl radicals has been accomplished under exogenous-oxidant- and metal-free conditions through the use ofnBu4NBr as a mediator. The resulting iminyl radicals undergo intramolecular cyclization smoothly with the adjacent (hetero)arenes to afford a series of indole-fused polycyclic compounds.
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).
