13993-17-4Relevant academic research and scientific papers
A mild, efficient and improved protocol for the synthesis of novel indolyl crown ethers, di(indolyl)pyrazolyl methanes and 3-alkylated indoles using H 4[Si(W3O10)3]
Murugan, Rajendran,Karthikeyan, Murugesan,Perumal, Paramasivam T.,Reddy, Boreddy S.R.
, p. 12275 - 12281 (2005)
Efficient electrophilic substitution reactions of indoles with various aldehydes proceed smoothly in acetonitrile using heteropoly acid (H 4[Si(W3O10)3]) to afford the corresponding new indolyl crown ethers and
Ruthenium-Catalyzed Cascade Annulation of Indole with Propargyl Alcohols
Kaufmann, Julia,J?ckel, Elisabeth,Haak, Edgar
, p. 5908 - 5911 (2018)
Cascade transformations forming multiple bonds and one-pot procedures provide rapid access to natural-product-like scaffolds from simple precursors. These atom-economic processes are valuable tools in organic synthesis and drug discovery. Herein, we report on ruthenium-catalyzed cascade annulations of indole with readily available propargyl alcohols. These provide rapid access to diverse carbazoles, cyclohepta[b]indoles, and further fused polycycles with high selectivity. A bifunctional ruthenium complex featuring a redox-coupled cyclopentadienone ligand acts as a common catalyst for the different cascade processes.
Nickel-Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
Brauer, Jan,Quraishi, Elisabeth,Kammer, Lisa Marie,Opatz, Till
supporting information, p. 18168 - 18174 (2021/11/30)
A simple visible light photochemical, nickel-catalyzed synthesis of ketones from carboxylic acid-derived precursors is presented. Hantzsch ester (HE) functions as a cheap, green and strong photoreductant to facilitate radical generation and also engages in the Ni-catalytic cycle to restore the reactive species. With this dual role, HE allows for the coupling of a large variety of radicals (1°,2°, benzylic, α-oxy & α-amino) with aroyl and alkanoyl moieties, a new feature in reactions of this type. With both precursors deriving from abundant carboxylic acids, this protocol is a welcome addition to the organic chemistry toolbox. The reaction proceeds under mild conditions without the need for toxic metal reagents or bases and shows a wide scope, including pharmaceuticals and complex molecular architectures.
Alkylation of Indoles with α,β-Unsaturated Ketones using Alumina in Hexanes
Zhang, Xiong,Jones-Mensah, Ebenezer,Deobald, Jackson,Magolan, Jakob
supporting information, p. 5548 - 5551 (2019/11/19)
We evaluated the influence of solvent on the alumina-promoted C3-alkylation of indoles with α,β-unsaturated ketones. We found that lipophilic solvents were generally superior to hydrophilic ones with hexanes offering the 3-alkyl indole products in high yields. Thus, we demonstrate an inexpensive and procedurally simple new process that pairs acidic alumina with hexanes to achieve this important Michael alkylation. The substrate scope includes twenty-four examples with reaction yields ranging from 61 to 96%. (Figure presented.).
An efficient water-mediated synthetic route for the alkylation of heteroarenes
Seyi?Tdanlio?lu, P?nar,Hanashalshahaby, Essam Hamied Ahmed,ünalero?lu, Canan
, p. 1598 - 1610 (2019/01/03)
An efficient synthetic route has been described for the alkylation of 1H-indole, 1H-benzimidazole, and 1H-benzotriazole. This approach features the alkylation of heteroaromatics through in situ generated enones from ketonic Mannich bases under metal-free conditions. A series of alkylated heteroaromatics have been synthesized via the K10 catalyzed alkylation reactions of these heteroaromatics with a variety of ketonic Mannich bases. Environmentally benign K10 catalyst, water-mediated mild reaction conditions, and the efficient synthesis of alkylated products are the advantages of this alkylation method.
Nickel-Catalyzed Coupling of Arylzinc Halides with Thioesters
Gehrtz, Paul H.,Kathe, Prasad,Fleischer, Ivana
supporting information, p. 8774 - 8778 (2018/06/26)
The Pd-catalyzed Fukuyama reaction of thioesters with organozinc reagents is a mild, functional-group-tolerant method for acylation chemistry. Its Ni-catalyzed variant might be a sustainable alternative to expensive catalytic Pd sources. We investigated the reaction of S-ethyl thioesters with aryl zinc halides with hetero- and homotopic Ni precatalysts and several ligands. The results show that both homo- and heterotopic species may contribute to catalysis. The substrate scope using an operationally homogeneous defined Ni complex was established. Acyl radicals are postulated as short-lived intermediates.
Concise Synthesis of Spiro[indoline-3,2′-pyrrolidine] and 1-Azacarbazole Derivatives via Copper-Catalyzed Cyclization of Indoles
Wang, Peng-Fei,Chen, Chao,Chen, Hui,Han, Li-Shuai,Liu, Liu,Sun, Hongbin,Wen, Xiaoan,Xu, Qing-Long
supporting information, p. 2339 - 2344 (2017/07/22)
A high-yielding, copper-catalyzed dearomatization reaction of indole from 2-methylindole-derived oxime acetates was realized, providing access to structurally novel spiro[indoline-3,2′-pyrrolidine] derivatives in 67–98% yields. When the C-2 position of the indole was not substituted, azacarbazole derivatives were obtained in moderate yields. This transformation provides an efficient approach to access nitrogen-containing spiroindolenine and azacarbazole derivatives with wide substrate scope. (Figure presented.).
Synthesis of 3,3-Spiroindolines via FeCl3-Mediated Cyclization of Aryl- or Alkene-Containing 3-Substituted N-Ac Indoles
Nandi, Raj Kumar,Guillot, Régis,Kouklovsky, Cyrille,Vincent, Guillaume
supporting information, p. 1716 - 1719 (2016/05/19)
We report the cyclization of 3-substituted N-acetylindoles for the straightforward synthesis of 3,3-spiroindolines via the Friedel-Crafts reaction of an appended aryl group or the formal [2 + 2] cycloaddition of an appended alkene. Our strategy involves a
Br2 as a novel Lewis acid catalyst for Friedel-Crafts alkylation of indoles with α,β-unsaturated ketones
Liang, Deqiang,Li, Xiangguang,Zhang, Wanshun,Li, Yanni,Zhang, Mi,Cheng, Ping
supporting information, p. 1027 - 1030 (2016/02/16)
The inexpensive Br2 can serve as a novel Lewis acid catalyst for Friedel-Crafts alkylation of indoles with α,β-unsaturated ketones. Under the catalysis of only 3 mol % of Br2, this Michael addition proceeded smoothly with high effici
Cu-catalyzed β-functionalization of saturated ketones with indoles: A one-step synthesis of C3-substituted indoles
Yang, Zhao,Liu, Chengkou,Zeng, Yu,Zhang, Jingming,Wang, Zhixiang,Fang, Zheng,Guo, Kai
, p. 89181 - 89184 (2016/10/03)
An effective one-pot synthesis of β-indolylketones from saturated ketones and indoles was developed. It is noteworthy that this methodology has a good functional group tolerance (alkyl, nitro, halogen, hydroxyl, methoxyl, carboxyl and ester) and is of great significance to the preparation of many indole heterocycles.
