- 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]
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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
- Murugan, Rajendran,Karthikeyan, Murugesan,Perumal, Paramasivam T.,Reddy, Boreddy S.R.
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- Ruthenium-Catalyzed Cascade Annulation of Indole with Propargyl Alcohols
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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.
- Kaufmann, Julia,J?ckel, Elisabeth,Haak, Edgar
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- Nickel-Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
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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.
- Brauer, Jan,Quraishi, Elisabeth,Kammer, Lisa Marie,Opatz, Till
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supporting information
p. 18168 - 18174
(2021/11/30)
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- Alkylation of Indoles with α,β-Unsaturated Ketones using Alumina in Hexanes
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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.).
- Zhang, Xiong,Jones-Mensah, Ebenezer,Deobald, Jackson,Magolan, Jakob
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supporting information
p. 5548 - 5551
(2019/11/19)
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- An efficient water-mediated synthetic route for the alkylation of heteroarenes
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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.
- Seyi?Tdanlio?lu, P?nar,Hanashalshahaby, Essam Hamied Ahmed,ünalero?lu, Canan
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p. 1598 - 1610
(2019/01/03)
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- Nickel-Catalyzed Coupling of Arylzinc Halides with Thioesters
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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.
- Gehrtz, Paul H.,Kathe, Prasad,Fleischer, Ivana
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supporting information
p. 8774 - 8778
(2018/06/26)
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- Concise Synthesis of Spiro[indoline-3,2′-pyrrolidine] and 1-Azacarbazole Derivatives via Copper-Catalyzed Cyclization of Indoles
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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.).
- Wang, Peng-Fei,Chen, Chao,Chen, Hui,Han, Li-Shuai,Liu, Liu,Sun, Hongbin,Wen, Xiaoan,Xu, Qing-Long
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supporting information
p. 2339 - 2344
(2017/07/22)
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- Synthesis of 3,3-Spiroindolines via FeCl3-Mediated Cyclization of Aryl- or Alkene-Containing 3-Substituted N-Ac Indoles
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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
- Nandi, Raj Kumar,Guillot, Régis,Kouklovsky, Cyrille,Vincent, Guillaume
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supporting information
p. 1716 - 1719
(2016/05/19)
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- Br2 as a novel Lewis acid catalyst for Friedel-Crafts alkylation of indoles with α,β-unsaturated ketones
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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
- Liang, Deqiang,Li, Xiangguang,Zhang, Wanshun,Li, Yanni,Zhang, Mi,Cheng, Ping
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supporting information
p. 1027 - 1030
(2016/02/16)
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- Cu-catalyzed β-functionalization of saturated ketones with indoles: A one-step synthesis of C3-substituted indoles
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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.
- Yang, Zhao,Liu, Chengkou,Zeng, Yu,Zhang, Jingming,Wang, Zhixiang,Fang, Zheng,Guo, Kai
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p. 89181 - 89184
(2016/10/03)
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- Palladium(II) in electrophilic activation of aldehydes and enones: Efficient C-3 functionalization of indoles
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The regioselective C-3 alkylation of indoles with aldehydes and enones as electrophiles is catalyzed by a d8 late transition metal complex PdCl2(MeCN)2 at room temperature in the presence of air/moisture and in the absence
- Mohapatra, Swapna Sarita,Mukhi, Priyabrata,Mohanty, Anuradha,Pal, Satyanarayan,Sahoo, Aditya Omprakash,Das, Debjit,Roy, Sujit
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supporting information
p. 5709 - 5713
(2015/09/29)
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- Al(OTf)3 catalysed Friedel-Crafts Michael type addition of indoles to α,β-unsaturated ketones with PEG-200 as recyclable solvent
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An Al(OTf)3 catalysed efficient Friedel-Crafts Michael type addition of indoles to α,β-unsaturated ketones using recyclable PEG-200 as an alternative reaction solvent is disclosed. The reaction under microwave irradiation is clean, leads to exc
- Gohain, Mukut,Jacobs,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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p. 1594 - 1599
(2014/01/23)
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- Heterobimetallic Pd-Sn catalysis: Michael addition reaction with C-, N-, O-, and S-nucleophiles and in situ diagnostics
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An efficient Michael addition reaction of differently substituted enones with carbon, sulfur, oxygen, and nitrogen nucleophiles has been achieved by a new heterobimetallic "Pd-Sn" catalyst system. The nature of the catalytically relevant species and their
- Das, Debjit,Pratihar, Sanjay,Roy, Sujit
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p. 2430 - 2442
(2013/04/23)
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- Csp2-Csp2 bond formation via Lewis acid/ammonium salt cocatalyzed tandem addition and oxidative dehydrogenation strategy: Alkenylation of indoles with α,β-unsaturated ketones
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The alkenylation of indoles with α,β-unsaturated ketones through a tandem addition and oxidative dehydrogenation strategy has been developed. This method provides an alternative approach for C3 alkenylation of indoles with α,β-unsaturated ketones. Using inexpensive and readily available BF3·Et2O and an ammonium salt as the efficient cocatalyst constitutes the attractive advantage of this reaction.
- Xiang, Shi-Kai,Wu, Guolin,Zhang, Bo,Cui, Yuxin,Jiao, Ning
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supporting information; experimental part
p. 3802 - 3804
(2012/09/21)
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- Ruthenium-catalyzed functionalization of pyrroles and indoles with propargyl alcohols
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Several ruthenium-catalyzed atom-economic transformations of propargyl alcohols with pyrroles or indoles leading to alkylated, propargylated, or annulated heteroaromatics are reported. The mechanistically distinct reactions are catalyzed by a single ruthenium(0) complex containing a redox-coupled dienone ligand. The mode of activation regarding the propargyl alcohols determines the reaction pathway and depends on the alcohols' substitution pattern. Secondary substrates form alkenyl complexes by a 1,2-hydrogen shift, whereas the transformation of tertiary substrates involves allenylidene intermediates. 1-Vinyl propargyl alcohols are converted by a cascade allylation/cyclization sequence. The environmentally benign processes are of broad scope and allow the selective synthesis of highly functionalized pyrroles and indoles generating water as the only waste product. Copyright
- Thies, Nora,Hrib, Cristian G.,Haak, Edgar
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supporting information; experimental part
p. 6302 - 6308
(2012/06/18)
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- ALLOSTERIC PROTEIN KINASE MODULATORS
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The invention provides specific small molecule compounds that allosterically regulate the activity or modulate protein-protein interactions of AGC protein kinases and the Aurora family of protein kinases, methods for their production, pharmaceutical compositions comprising same, and their use for preparing medicaments for the treatment and prevention of diseases related to abnormal activities of AGC protein kinases or of protein kinases of the Aurora family.
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Page/Page column 141
(2010/04/30)
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- 3,5-Diphenylpent-2-enoic acids as allosteric activators of the protein kinase PDK1: Structure-activity relationships and thermodynamic characterization of binding as paradigms for PIF-binding pocket-targeting compounds
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The modulation of protein kinase activities by low molecular weight compounds is a major goal of current pharmaceutical developments. In this line, important efforts are directed to the development of drugs targeting the conserved ATP binding site. Howeve
- Stroba, Adriana,Schaeffer, Francis,Hindie, Valerie,Lopez-Garcia, Laura,Adrian, Iris,Fr?hner, Wolfgang,Hartmann, Rolf W.,Biondi, Ricardo M.,Engel, Matthias
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supporting information; experimental part
p. 4683 - 4693
(2010/02/28)
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- Thermal rearrangement of indolyl oxime esters to pyridoindoles
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(Chemical Equation Presented) Acyl oximes derived from a variety of indolylalkanones underwent a ring closure sequence during FVP to afford 9H-pyrido[2,3-b]indoles. Unlike UV light promoted reactions of oxime esters, the mechanism is almost certainly not mediated by iminyl radicals but probably involves tautomerism, elimination of acetic acid, and a final electrocyclic ring closure.
- Portela-Cubillo, Fernando,Surgenor, Brian A.,Aitken, R. Alan,Walton, John C.
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p. 8124 - 8127
(2008/12/22)
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- Conjugate addition of indoles with electron-deficient olefins catalyzed by Fe-exchanged montmorillonite K10
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Conjugate addition of indoles with a variety of electron-deficient olefins in the presence of Fe-exchanged montmorillonite K10 affords the corresponding Michael adduct in excellent yields with high selectivity. The catalyst was also found to be recyclable
- Singh, Devendrapratap U.,Singh, Pankajkumar R.,Samant, Shriniwas D.
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p. 1265 - 1271
(2007/10/03)
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- Highly efficient construction of benzene ring in carbazoles by palladium-catalyzed endo-mode oxidative cyclization of 3-(3′-alkenyl) indoles
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A highly efficient construction of the benzene ring in carbazoles by palladium-catalyzed endo-mode oxidative cyclization of 3-(3′-alkenyl)- indoles was developed. The reaction utilizes benzoquinone as the stoichiometric oxidant and is conducted under mild conditions.
- Kong, Aidi,Han, Xiuling,Lu, Xiyan
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p. 1339 - 1342
(2007/10/03)
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- Conjugate addition of indoles and thiols with electron-deficient olefins catalyzed by Bi(OTf)3
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Conjugate addition of indoles and thiols with a variety of electron-deficient olefins mediated by a catalytic amount of Bi(OTf)3 at ambient temperature to afford the corresponding Michael adducts in good to excellent yields with high selectivity is reported.
- Alam, M. Mujahid,Varala, Ravi,Adapa, Srinivas R.
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p. 5115 - 5119
(2007/10/03)
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- InCl3-catalysed conjugate addition of indoles with electron-deficient olefins
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Indole and 2-methylindole undergo conjugate addition with electron-deficient olefins in the presence of a catalytic amount of InCl3 at ambient temperature to afford the corresponding Michael adducts in excellent yields with high selectivity.
- Yadav,Abraham,Reddy,Sabitha
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p. 2165 - 2169
(2007/10/03)
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