16886-08-1Relevant articles and documents
Iodine-Catalyzed Aerobic Diazenylation-Amination of Indole Derivatives
Sar, Saibal,Tripathi, Ankita,Dubey, Kshatresh Dutta,Sen, Subhabrata
, p. 3748 - 3756 (2020)
A mild strategy for consecutive diazenylation and amination of indole moieties has been demonstrated. The functionalization occurs at C3 and C2 carbon atoms, respectively, at the indole scaffold in the presence of catalytic iodine and air at 40 °C in the 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) solvent. It is noteworthy that the aromatic amines are generated in situ by the reaction of aryl hydrazine with iodine. In general, bright red products are obtained in moderate to good yield. Control reactions are conducted to establish the reaction mechanism.
Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
Liu, Shuyang,Tian, Miao,Bu, Xiubin,Tian, Hua,Yang, Xiaobo
supporting information, p. 7738 - 7744 (2021/05/07)
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.
Manganese(III) Acetate Catalyzed Aerobic Dehydrogenation of Tertiary Indolines, Tetrahydroquinolines and an N-Unsubstituted Indoline
Niu, Xiaokang,Yang, Lei
supporting information, p. 4209 - 4215 (2021/08/06)
A Mn(OAc)3 ? 2H2O-catalyzed aerobic dehydrogenation of five and six-membered N-heterocycles for the synthesis of N-heteroarenes is reported. Of note, this protocol can be applied to the dehydrogenation of tertiary indolines with various electron-deficient N-substituents. Preliminary mechanistic investigations support that a single-electron transfer pathway might be involved. (Figure presented.).
Synthesis of 3-halogenated 2,3′-biindoles by a copper-mediated 2,3-difunctionalization of indoles
Gu, Xiaoting,Liang, Taoyuan,Wei, Wanxing,Zhang, Xiaoxiang,Zhang, Yingying,Zhang, Zhuan
supporting information, p. 10403 - 10407 (2021/12/17)
A copper-mediated 2,3-difunctionalization of indoles to afford 3-halogenated 2,3′-biindoles is described herein. The protocol uses readily available feedstocks and a naturally abundant copper catalyst system, which allows the regioselective formation of C-C and C-X (X = Cl & Br) bonds in one single operation. Here the copper metal salt serves not only as a catalyst but also as a reactant to provide the source of halogen. This operationally simple procedure avoids the utilization of environmentally unfriendly reagents and displays good functional group compatibility. Noteworthily, the introduction of halogen into molecules would offer great potential for further chemical transformations. This journal is
Metal-Free C?H Borylation of N-Heteroarenes by Boron Trifluoride
Iashin, Vladimir,Berta, Dénes,Chernichenko, Konstantin,Nieger, Martin,Moslova, Karina,Pápai, Imre,Repo, Timo
supporting information, p. 13873 - 13879 (2020/10/02)
Organoboron compounds are essential reagents in modern C?C coupling reactions. Their synthesis via catalytic C?H borylation by main group elements is emerging as a powerful tool alternative to transition metal based catalysis. Herein, a straightforward metal-free synthesis of aryldifluoroboranes from BF3 and heteroarenes is reported. The reaction is assisted by sterically hindered amines and catalytic amounts of thioureas. According to computational studies the reaction proceeds via frustrated Lewis pair (FLP) mechanism. The obtained aryldifluoroboranes are further stabilized against destructive protodeborylation by converting them to the corresponding air stable tetramethylammonium organotrifluoroborates.
Sulfoxide-Promoted Chlorination of Indoles and Electron-Rich Arenes with Chlorine as Nucleophile
Ji, Yuan-Zhao,Li, Hui-Jing,Wang, Yi-Ruo,Wu, Yan-Chao,Zhang, Zheng-Yan
supporting information, (2020/02/05)
An efficient chlorination of indoles and electron-rich arenes with chlorine anion as nucleophile is described. With the use of ethyl phenyl sulfoxide as the promoter, the reaction went smoothly under metal-free and mild conditions. Various indoles and electron-rich arenes are converted into the corresponding chlorinated compounds in moderate to excellent yields. A plausible interrupted Pummerer reaction mechanism was proposed without the oxidation of chloride anion. In addition, the byproduct thioether could be easily converted to the starting material sulfoxide just by a simple oxidation reaction. (Figure presented.).
Synthesis of Cyclopenta[b]indoles via a Formal [3+2] Cyclization of N-Sulfonyl-1,2,3-triazoles and Indoles
Duan, Shengguo,Zhang, Wan,Hu, Yuntong,Xu, Ze-Feng,Li, Chuan-Ying
supporting information, p. 3570 - 3575 (2020/08/05)
Annulation of benzoxy-tethered N-sulfonyl-1,2,3-triazoles and indoles has been developed in this paper, providing an efficient and convenient access to valuable cyclopenta[b]indoles in moderate to good yields. α,β-Unsaturated imine, which generated in situ from denitrogenation and 1,2-OBz migration of triazole, provided three carbons for the formal [3+2] cyclization reaction for the first time. (Figure presented.).
Enantioselective Construction of Si-Stereogenic Center via Rhodium-Catalyzed Intermolecular Hydrosilylation of Alkene
He, Tao,Liu, Li-Chuan,Ma, Wen-Peng,Li, Bin,Zhang, Qing-Wei,He, Wei
supporting information, p. 17011 - 17015 (2020/11/30)
Catalytic, enantioselective synthesis of stereogenic silicon compounds remains a challenge. Herein, we report a rhodium-catalyzed regio- and enantio-selective intermolecular hydrosilylation of alkene with prochiral dihydrosilane. This new method features a simple catalytic system, mild reaction conditions and a wide functional group tolerance.
γ-Carboline synthesis enabled by Rh(iii)-catalysed regioselective C-H annulation
Jiang, Bo,Jia, Jingwen,Sun, Yufei,Wang, Yichun,Zeng, Jing,Bu, Xiubin,Shi, Liangliang,Sun, Xiaoying,Yang, Xiaobo
supporting information, p. 13389 - 13392 (2020/11/10)
A redox-neutral Rh(iii)-catalyzed C-H annulation of indolyl oximes was developed. Relying on the use of various alkynyl silanes as the terminal alkyne surrogates, the reaction exhibited a reverse regioselectivity, thus giving an exclusive and easy way for the synthesis of a wide range of substituent free γ-carbolines at C3 position with high efficiency. Deuterium-labelling experiments and kinetic analysis have preliminarily shed light on the working mode of this catalytic system. This journal is
Cobalt-Catalyzed Cycloamination: Synthesis and Photophysical Properties of Polycyclic N-Heterocycles
Dong, Yu,He, Shuai,Shi, Zhi-Chuan,Wang, Ji-Yu,Yang, Jian,Zhan, Xiao-Yu,Zhang, Hua,Zhang, Xiao-Mei
supporting information, (2020/07/15)
The first earth-abundant cobalt-catalyzed cycloamination of indolylquinones and various (hetero)aromatic amine under ligand-free conditions for the synthesis of polycyclic N-heterocycles has been developed. The process allows facile access to polycyclic N-heterocycles with tolerance of chloride, bromide, amino, thio, etc. groups in moderate to high yields (up to 89percent). In addition, The photophysical properties of the synthesized products were evaluated. These products exhibit interesting fluorescence properties, which is promising for fluorescent probes.
