36684-65-8Relevant academic research and scientific papers
Tetrahydrocarbazoles by mechanochemical Fischer indolisation
Qiu, Yichen,Puni, Kararaina Te,Duplan, Clotilde C.,Lindsay, Ashley C.,Sperry, Jonathan
supporting information, (2021/05/26)
The Fischer indolisation (FI) typically proceeds in the presence of a Br?nsted or Lewis acid in an organic solvent at elevated temperatures. Herein, we report that tetrahydrocarbazoles (THCs) are accessible by mechanochemical FI at ambient temperature. Using phenylhydrazine hydrochlorides in the presence of silica is critical for this solid-state variant of the FI.
Direct Synthesis of Indoles from Azoarenes and Ketones with Bis(neopentylglycolato)diboron Using 4,4′-Bipyridyl as an Organocatalyst
Misal Castro, Luis C.,Sultan, Ibrahim,Nishi, Kohei,Tsurugi, Hayato,Mashima, Kazushi
, p. 3287 - 3299 (2021/03/01)
Multifunctionalized indole derivatives were prepared by reducing azoarenes in the presence of ketones and bis(neopentylglycolato)diboron (B2nep2) with a catalytic amount of 4,4′-bipyridyl under neutral reaction conditions, where 4,4′-bipyridyl acted as an organocatalyst to activate the B-B bond of B2nep2 and form N,N′-diboryl-1,2-diarylhydrazines as key intermediates. Further reaction of N,N′-diboryl-1,2-diarylhydrazines with ketones afforded N-vinyl-1,2-diarylhydrazines, which rearranged to the corresponding indoles via the Fischer indole mechanism. This organocatalytic system was applied to diverse alkyl cyclic ketones, dialkyl, and alkyl/aryl ketones, including heteroatoms. Methyl alkyl ketones gave the corresponding 2-methyl-3-substituted indoles in a regioselective manner. This protocol allowed us to expand the preparation of indoles having high compatibility with not only electron-donating and electron-withdrawing groups but also N- and O-protecting functional groups.
Design, synthesis, in vivo and in vitro studies of 1,2,3,4-tetrahydro-9H-carbazole derivatives, highly selective and potent butyrylcholinesterase inhibitors
Ghobadian, Roshanak,Esfandyari, Roghaieh,Nadri, Hamid,Moradi, Alireza,Mahdavi, Mohammad,Akbarzadeh, Tahmineh,Khaleghzadeh-Ahangar, Hossein,Edraki, Najmeh,Sharifzadeh, Mohammad,Amini, Mohsen
, p. 211 - 223 (2019/04/17)
Abstract: Inhibition of butyrylcholinesterase (BChE) might be a useful therapeutic target for Alzheimer’s disease (AD). A new series of 1,2,3,4-tetrahydro-9H-carbazole derivatives were designed synthesized and evaluated as BChE inhibitors. While all of the derivatives have shown for AChE IC50 values below the detectable limit (> 100?μM), they were selective potent BChE inhibitors. 1-(2-(6-fluoro-1,2,3,4-tetrahydro-9H-carbazole-9-yl)ethyl)piperidin-1-ium chloride (15?g) had the most potent anti-BChE activity (IC50 value = 0.11?μM), the highest BChE selectivity and mixed-type inhibition. Pharmacokinetic properties were accordant to Lipinski rule and compound 15g demonstrated neuroprotective and inhibition of β-secretase (BACE1) activities. Furthermore, in vivo study of compound 15g in Morris water maze task has confirmed memory improvement in scopolamine-induced impairment. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD. Graphical abstract: A new series of 1,2,3,4-tetrahydro-9H-carbazole derivatives were designed synthesized and evaluated as BChE inhibitors. While all of the derivatives have shown for AChE IC50 values below the detectable limit, they were selective potent BChE inhibitors. Compound 15g had the most potent anti-BChE activity. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD.[Figure not available: see fulltext.]
Annulation of Indoles with 1,n-Dibromoalkanes by a Pd(II)-Catalyzed and Norbornene-Mediated Reaction Cascade
Bach, Thorsten,Henkel, Michael
, p. 1231 - 1238 (2020/04/15)
Employing 1,3-dibromopropane, 1,4-dibromobutane, and 1,5-dibromopentane as biselectrophiles, the annulation of indoles was probed in the presence of PdCl 2 (MeCN) 2 as a catalyst and norbornene as a transpositional ligand. Ring formation to a five-membered ring was observed at positions C2 and N, while annulation of a six-membered ring occurred at positions C2 and C3. The latter cascade process was successfully applied to the direct synthesis of 1,2,3,4-tetrahydrocarbazoles from indoles (11 examples, 31-68% yield). Seven-membered-ring annulation was feasible by an initial coupling at positon C2 followed by alkylation at C3.
SBA-15-Pr-SO3H catalyzed one-pot synthesis of indole derivatives via Fischer indole pathway
Ghiyasabadi, Zahra,Bahadorikhalili, Saeed,Saeedi, Mina,Karimi-Niyazagheh, Mona,Mirfazli, Seyedeh Sara
supporting information, p. 606 - 610 (2020/01/03)
In this work, an efficient, user-friendly, and simple procedure was reported for the preparation of indole derivatives catalyzed by the heterogeneous SBA-15-Pr-SO3H via Fischer indole pathway. The title compounds were synthesized from various arylhydrazines and ketones in the presence of 3 mol% of the catalyst in the refluxing ethanol.
Synthesis and evaluation of indole derivatives as photosynthesis and plant growth inhibitors
Mendes, Mylla Cristie Da Silva,Fazolo, Bruno Rodrigues,De Souza, Jéssica Maria,De Vasconcelos, Leonardo Gomes,De Sousa Junior, Paulo Teixeira,Dall'Oglio, Evandro Luiz,Soares, Marcos Ant?nio,Sampaio, Olívia Moreira,Vieira, Lucas Campos Curcino
, p. 1350 - 1358 (2019/06/19)
Indole derivatives were synthetized based on the Fischer indole methodology using different phenyl hydrazine hydrochlorides and either cyclohexanone or 2-butanone. The pre- and post-emergent herbicidal activities were evaluated against Ipomoea grandifolia. A carbazole, 6-chloro-2,3,4,9-tetrahydro-1H-carbazole (3b), decreased the PIabs parameter by 32% and increased the cross-section related parameters, indicating the inactivation of the reaction center on photosystem II. Compound 3b acts as a post-emergent herbicide prototype since dry biomass was reduced by 50%, corroborating the fluorescence results. Comparing instead with a germination experiment, 2,3,4,9-tetrahydro-1H-carbazole (3a) was found to be the most effective agent, inhibiting seed germination by 22% and decreasing root length by 50%. The tetrahydrocarbazoles showed better results than indole derivatives potentially due to the presence of methylene groups at structures, which increase the compounds' lipophilicity and may facilitate their access to the plant. In addition, electron withdrawing groups on the aromatic ring were found to correlate with increased herbicide activity. Further optimization of this series towards the development of herbicides is ongoing.
Catalytic Oxidative Coupling Cyclization for Construction of Benzofuroindolenines under Mild Reaction Conditions
Lin, Yuqi,Ye, Jinxiang,Zhang, Wenting,Gao, Yu,Chen, Haijun
supporting information, p. 432 - 435 (2018/12/13)
We describe iron-catalyzed oxidative coupling cyclization of tetrahydrocarbazoles or THβCs or THγCs to form benzofuroindolenines as fused polycyclic indoles. This mild, efficient and simple approach afforded a library of more than 52 complex compounds across a range of substrate classes with good to excellent yields. (Figure presented.).
Copper(II) catalyzed aromatization of tetrahydrocarbazole: An unprecedented protocol and its utility towards the synthesis of carbazole alkaloids
Dalvi, Bhakti A.,Lokhande, Pradeep D.
supporting information, p. 2145 - 2149 (2018/05/08)
An efficient protocol for the aromatization of tetrahydrocarbazole is described by using catalytic copper(II) chloride dihydrate in DMSO. This newly established methodology has utilized towards the synthesis of naturally occurring carbazole alkaloids, namely 3-methylcarbazole, 3-formyl carbazole, glycozoline, glycozolicine and clauszoline-K. In addition, the protocol is generalized for the aromatization of N-substituted tetrahydrocarbazole, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline and 1,2,3,4-tetrahydro β-carboline to give the corresponding heteroaromatic compounds from very good to excellent yield. Moreover, this method has been proven to be tolerant to a broad range of functional groups with excellent yields.
An Electrophilic Bromine Redox Catalysis for the Synthesis of Indole Alkaloid Building Blocks by Selective Aliphatic C?H Amination
Bergès, Julien,García, Belén,Mu?iz, Kilian
supporting information, p. 15891 - 15895 (2018/11/23)
A new homogeneous bromine(?I/I) redox catalysis is described, which is based on monomeric bromine(I) compounds containing transferable phthalimidato groups. These catalysts enable intermolecular C?H amination reactions at previously unaccessible aliphatic positions and thus enlarge the synthetic potential of direct C?N bond formation, including its application in the synthesis of alkaloid building blocks. This aspect is demonstrated by a new synthetic approach to aspidospermidine. In addition to the development of the catalyst system, the structures of the involved bromine(I) key catalysts were fully elucidated, including by X-ray analyses.
Design, synthesis and pharmacological evaluation of some novel tetrahydrocarbazoles as potential COX-2 inhibitors
Sakinala, Padmavathi,Chikhale, Rupesh,Tajne, Madhukar
, p. 437 - 449 (2018/04/20)
Background: NSAIDs have been extensively used for the treatment of pain and inflammation. There are about 30 different NSAIDs available in market and about 80 percent of prescriptions throughout the world contains one or the other painkiller. Chronic use of these drugs has many side effects such as gastric ulceration and the COX-2 inhibitors suffer from major drawback of cardiac toxicity. The need for a potential and safe NSAIDs has always led to the development of newer, better and safer drug molecules. In this article design and development of tetrahydrocarbazole derivatives with very low ulcerative index is reported. Methods: Fifteen tetrahydrocarbazole derivatives were synthesized on the basis of structural homology to indomethacin. Compounds were synthesized and characterized on the basis of spectral data. These were studied for their analgesic, anti-inflammatory and ulcerogenic activities. These compounds were subjected to molecular docking studies for understanding the possible mechanism of action and target. Results: The designed compounds were synthesized successfully in good yield and purity without much efforts. All compounds were evaluated by in vitro and in vivo assay, molecular modelling studies and ulcerative index. One of the compound (3-Aminophenyl) (6-chloro-1,2,3,4-tetrahydro-9H-carbazol-9-yl) methanone 13 was found to be highly active in the in vitro and in vivo assessment also it was found to be highly safe on ulcerogenic index compared to the standard drugs. Conclusion: Tetrahydrocarbazoles were found to be promising scaffolds which can be developed into safe and potential non-steroidal anti-inflammatory agents.
