1202-04-6Relevant articles and documents
Metal-free N-arylation of indolines with diaryliodonium salts
Riedmüller, Stefan,Nachtsheim, Boris J.
, p. 651 - 655 (2015)
The N-arylation of indolines using diaryliodonium salts as electrophilic arylating reagents is described. Without the use of any additional additives, the desired N-aryl indolines could be obtained in up to 85% yield.
Synthesis, spectroscopic identification and molecular docking of certain N-(2-[2-(1H-Indol-2-ylcarbonyl) hydrazinyl](oxo)acetyl phenyl)acetamides and N-[2-(2-[2-(Acetylamino)phenyl](oxo)acetyl hydrazinyl)-2-oxoethyl]-1H-indole-2-carboxamides: New antimicrobial agents
Almutairi, Maha S.,Zakaria, Azza S.,Al-Wabli, Reem I.,Hubert Joe,Abdelhameed, Ali S.,Attia, Mohamed I.
, (2018)
N-(2-[2-(1H-Indol-2-ylcarbonyl)hydrazinyl](oxo)acetyl phenyl)acetamides (5a–h) and N-[2-(2-[2-(acetylamino)phenyl](oxo)acetyl hydrazinyl)-2-oxoethyl]-1H-indole-2-carboxamides (5i–l) were synthesized and characterized with different analytical tools. N-Acetylisatines 4a–d were subjected to ring opening at their C2 carbons with the aid of different indole-bearing hydrazides 3a,b and 7 to afford the respective glyoxylamides 5a–l. The antimicrobial activity of the target compounds 5a–l was assessed with the aid of Diameter of the Inhibition Zone (DIZ) and Minimum Inhibitory Concentration (MIC) assays against a panel of Gram-positive and Gram-negative bacteria and certain fungal strains. The antimicrobial screening revealed that Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans are the most sensitive microorganisms towards the synthesized compounds 5a–l. In addition, compounds 5c and 5h emerged as the most active congeners towards Staphylococcus aureus and Candida albicans, respectively. Molecular docking studies revealed the possible binding mode of compounds 5c and 5h to their target proteins.
A General Non-Reductive Method for the Desulfenylation of 3-Indolyl Sulfides
Hamel, Pierre,Zajac, Nicolas,Atkinson, Joseph G.,Girard, Yves
, p. 2059 - 2062 (1993)
In trifluoroacetic acid, in the presence of thiosalicyclic acid as a trapping agent, 3-indolyl sulfides bearing a wide variety of substituents are smoothly and rapidly desulfenylated to the corresponding 3-unsubstituted indoles.
Synthesis of isobrassilexin, a biologically active isomer of brassilexin, a cruciferae phytoalexin
Barbier,Devys,Tempete,Kollmann,Bousquet
, p. 3109 - 3117 (1993)
The synthesis of isobrassilexin 2, a hitherto non natural indoloisothiazole is reported (two steps, 43% yield). This substance, an isomer of brassilexin 1 has shown important biological properties in vitro.
Rapid and easy access to indoles via microwave-assisted Hemetsberger-Knittel synthesis
Lehmann, Frank,Holm, Melanie,Laufer, Stefan
, p. 1708 - 1709 (2009)
Hemetsberger-Knittel indole synthesis can be carried out under microwave activation. The optimum reaction conditions were found by using different solvents and by varying irradiation times and temperature. After 10 min of microwave irradiation, high conversion into the corresponding indole products was achieved without formation of any side products.
Synthesis of enynoindoles via vinyl and ethynyl indoles
Pérez-Serrano, Leticia,Casarrubios, Luis,Domínguez, Gema,González-Pérez, Patxi,Pérez-Castells, Javier
, p. 1810 - 1812 (2002)
A convenient synthesis of indoles bearing allyl, ethynyl, and/or propargyl moieties is described starting from indole or indole-2-carboxylic acid.
Base-assisted intramolecular c-n coupling reaction from nh2-bound cyclopalladated l -phenylalanine to indoline-2-carboxylic acid
Afonso, Carlos,Brière, Jean-Fran?ois,Coufourier, Sébastien,Gandon, Vincent,Hoarau, Christophe,Jacquin-Labarre, Aurélien,Journot, Guillaume,Le Foll, Alexandra,Levacher, Vincent,Tamion, Rodolphe
, p. 767 - 773 (2020)
The deprotonative intramolecular-amination reaction of phenylalanine-derived palladacycles has been investigated to highlight a facile carbonate-assisted N-H activation before the C-N bond formation. A major counterion effect led to divergent pathways whereby the SPhos-Pd complexes with iodine, triflate, or trifluoroacetate anions were key intermediates to afford access to (S)-2-indolinecarboxylic acid derivatives.
A Novel Sc(OTf)3-Catalyzed (2+2+1)-Cycloannulation/Aza-Friedel–Crafts Alkylation Sequence toward Multicyclic 2-Pyrrolines
Schlegel, Marcel,Coburger, Peter,Schneider, Christoph
, p. 14207 - 14212 (2018)
The rapid assembly of molecular complexity continues to be at the forefront of novel reaction development. In the pursuit of that goal, we herein report a novel Sc(OTf)3-catalyzed, one-pot multicomponent reaction that furnishes complex multicyclic 2-pyrrolines with excellent overall yields and perfect diastereocontrol. This process is based on our previously established (2+2+1)-cycloannulation of in situ generated 1-azaallyl cations, 1,3-dicarbonyls and primary amines. The newly formed and highly reactive aminal moiety is readily substituted with indoles and pyrroles both as external and internal π-nucleophiles to provide densely functionalized N-heterocycles with four new σ-bonds and two vicinal quaternary stereogenic centers. In addition, DFT calculations have been conducted to further characterize the intermediate 1-azaallyl cations.
Enantioselective arylative dearomatization of indoles via pd-catalyzed intramolecular reductive heck reactions
Shen, Chong,Liu, Ren-Rong,Fan, Ren-Jie,Li, Ying-Long,Xu, Teng-Fei,Gao, Jian-Rong,Jia, Yi-Xia
, p. 4936 - 4939 (2015)
A highly enantioselective intramolecular arylative dearomatization of indoles via palladium-catalyzed reductive Heck reactions was developed. The new strategy led to a series of optically active indolines bearing C2-quaternary stereocenters in modest to good yields with excellent enantioselectivities (up to 99% ee).
Synthesis of new functionalized indoles based on ethyl indol-2-carboxylate
Boraei, Ahmed T. A.,El Ashry, El Sayed H.,Barakat, Assem,Ghabbour, Hazem A.
, (2016)
Successful alkylations of the nitrogen of ethyl indol-2-carboxylate were carried out using aq. KOH in acetone. The respective N-alkylated acids could be obtained without separating the N-alkylated esters by increasing the amount of KOH and water. The use of NaOMe in methanol led to transesterification instead of the alkylation, while the use of NaOEt led to low yields of the N-alkylated acids. Hydrazinolysis of the ester gave indol-2-carbohydrazide which then was allowed to react with different aromatic aldehydes and ketones in ethanol catalyzed by acetic acid. Indol-2-thiosemicarbazide was used in a heterocyclization reaction to form thiazoles. The new structures were confirmed using NMR, mass spectrometry and X-ray single crystal analysis.
Binding trimethyllysine and other cationic guests in water with a series of indole-derived hosts: Large differences in affinity from subtle changes in structure
Whiting, Amanda L.,Hof, Fraser
, p. 6885 - 6892,8 (2012)
The binding of a series of indole-derived hosts to various ammonium cations in pure, buffered water is investigated using both solution phase 1H NMR studies and computational modeling. These hosts can engage their targets via the cation-pi interaction, electrostatic attraction, and the hydrophobic effect. The hydrophobic effect is shown to be a dominant influence in the strength of the binding interactions, both in terms of the hydrophobicity of the host and of the guest. Our findings show that small changes that reduce the host hydrophobic surface area without reducing either the number of negative charges or amount of aromatic surface area are found to significantly decrease binding. Additionally, the position of solubilizing charges is also shown to influence the preferred host geometry and resulting binding constants.
Palladium-catalyzed tandem C,N-arylation of immobilized enamine for solid phase indole synthesis
Yamazaki, Kazuo,Nakamura, Yosuke,Kondo, Yoshinori
, p. 2137 - 2138 (2002)
Intramolecular palladium-catalyzed N-arylation of immobilized dehydrohalophenylalaninate was found to proceed smoothly to form indolecarboxylates. The method was successfully combined with the Heck reaction to perform one pot indole synthesis via palladium-catalyzed tandem C,N-arylation reactions.
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
supporting information, p. 4876 - 4894 (2021/09/20)
Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
-
Paragraph 0175; 0186-0187; 0261-0262, (2021/06/22)
The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
