19005-93-7Relevant articles and documents
Molecular Structure and Photochemistry of (E)- and (Z)-Ethyl 3-(2-Indolyl)propenoate. Ground State Conformational Control of Photochemical Behavior and One-Way E -> Z Photoisomerization
Lewis, Frederick D.,Yang, Jye-Shane
, p. 14560 - 14568 (1996)
The molecular structure, electronic spectra, and photoisomerization of (E)- and (Z)-ethyl 3-(2-indolyl)propenoate, two methylated indole derivatives, and their N,N-dimethylamide analog have been investigated.The E ester exists in the ground state as a mixture of anti and syn rotational isomers.The spectroscopic and photochemical behaviors of the individual anti and syn conformers were characterized with the assistance of comparisons with the behavior of the methylated indole derivatives.The major anti conformer of the E ester absorbs and emits at shorter wavelength than the minor syn conformer.The rate constant for singlet state isomerization of the anti conformer is substantially larger than that of the syn conformer, resulting in a shorter singlet lifetime and smaller fluorescence quantum yield for the anti conformer.The behavior of the E amide in both the ground and excited states is similar to that of the ester.The Z isomers of the ester and amide possess a relatively strong intramolecular hydrogen bond.Their singlet states are weakly fluoroscent and photoisomerize ineffeciently in nonpolar solvents.Thus photostationary states highly enriched in the Z isomers are obtained in nonpolar solvents.The red-shifted, structureless emission observed upon irradiating the Z amide in an EPA or methylcyclohexane glass at 77 K is attributed to an excited state tautomer formed via intramolecular hydrogen transfer.
Synthesis and evaluation of cyclic nitrone derivatives as potential anti-cancer agents
Zhou, Wei,Ju, Dongyan,Ao, Yuhui,Liu, Yu,Zhao, Jinbo
, p. 1309 - 1316 (2021/05/27)
Nitrones have been found to exhibit attractive biological values as immuno spin trapping agents. However, successful clinical cases of nitrone therapeutics are still lacking. Herein we report the synthesis and antiproliferative activity of a series of structurally diverse nitrone derivatives against a panel of 5 cancer cell lines, based on which indole- and pyrrole-fused were further evaluated by analogue preparation and in-vitro screening. Analogues with moderate to good potency were identified. This study shows the promise for further pursuit of nitrone-type small molecules in chemotherapy. [Figure not available: see fulltext.]
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.
Amide-Amine Replacement in Indole-2-carboxamides Yields Potent Mycobactericidal Agents with Improved Water Solubility
Tan, Yu Jia,Li, Ming,Gunawan, Gregory Adrian,Nyantakyi, Samuel Agyei,Dick, Thomas,Go, Mei-Lin,Lam, Yulin
, p. 704 - 712 (2020/11/30)
Indolecarboxamides are potent but poorly soluble mycobactericidal agents. Here we found that modifying the incipient scaffold by amide-amine substitution and replacing the indole ring with benzothiophene or benzoselenophene led to striking (10-20-fold) im
