- PECULIARITIES OF NUCLEOPHILIC SUBSTITUTION IN INDOLYLIODONIUM SALTS
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3-Indolylphenyliodoniun trifluoroacetate reacts with ammonium bromide and lithium chloride and bromide to give 3-haloindoles.The reaction with ammonium chloride and tetrabutylammonium chloride leads to a mixture of 2- and 3-chloroindoles.The same mixture of chloroindoles is also formed by the action of lithium chloride but in the presence of 15-crown-5 ether.The course of the reaction is explained by ambident reaction of the iodonium salt.
- Budylin, V. A.,Ermolenko, M. S.,Chugtai, F. A.,Kost, A. N.
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Read Online
- Fast halogenation of some N-heterocycles by means of N,N'-dihalo-5,5- dimethylhydantoin
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An instantaneous, selective and high-yielding halogenation process is reported. The method operates with imidazoles, pyrazoles, and indoles under benign reaction conditions. The developed process involves the use of N,N'-dihalo-5,5-dimethylhydantoins (halo=chlorine, bromine, iodine) as halogenation reagents that are activated by catalytic quantities of a strong Bronsted acid. Moreover, the halogenation process is switchable to produce either the mono- or di-halogenated products. Issues related to the reaction mechanism are investigated and a proposal for a reaction mechanism is disclosed.
- Sandtorv, Alexander H.,Bjorsvik, Hans-Rene
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Read Online
- A flavin-dependent halogenase from metagenomic analysis prefers bromination over chlorination
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Flavin-dependent halogenases catalyse halogenation of aromatic compounds. In most cases, this reaction proceeds with high regioselectivity and requires only the presence of FADH2, oxygen, and halide salts. Since marine habitats contain high concentrations of halides, organisms populating the oceans might be valuable sources of yet undiscovered halogenases. A new Hidden-Markov-Model (HMM) based on the PFAM tryptophan halogenase model was used for the analysis of marine metagenomes. Eleven metagenomes were screened leading to the identification of 254 complete or partial putative flavin-dependent halogenase genes. One predicted halogenase gene (brvH) was selected, codon optimised for E. coli, and overexpressed. Substrate screening revealed that this enzyme represents an active flavin-dependent halogenase able to convert indole to 3-bromoindole. Remarkably, bromination prevails also in a large excess of chloride. The BrvH crystal structure is very similar to that of tryptophan halogenases but reveals a substrate binding site that is open to the solvent instead of being covered by a loop.
- Neubauer, Pia R.,Widmann, Christiane,Wibberg, Daniel,Schr?der, Lea,Frese, Marcel,Kottke, Tilman,Kalinowski, J?rn,Niemann, Hartmut H.,Sewald, Norbert
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Read Online
- Synthesis of antifungal N-isoprenyl-indole alkaloids from the fungus Aporpium caryae
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The synthesis of two antifungal alkaloids 1 and 2 is described. It involves the N-isoprenyl-indole brominated key-intermediate 3 prepared by introduction of the isoprenyl group on the indole core itself.
- Della Sala, Giorgio,Capozzo, Daniela,Izzo, Irene,Giordano, Assunta,Iommazzo, Antonella,Spinella, Aldo
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Read Online
- Electrochemical umpolung of bromide: Transition-metal-free bromination of indole C–H bond
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A facile and sustainable electrochemical umpolung of bromide ion protocol was developed under mild reaction conditions. Transition metal catalysts and exogenous chemical oxidants were obviated for the bromination of C–H bond. Notably, graphite rod, which is commercially available at supermarkets and is inexpensive, was employed as the electrode material. This operationally easy and environmentally friendly approach accomplished the synthesis of 3-bromoindole in excellent yield and regioselectivity.
- Zhang, Pan,Chen, Jianbin,Gao, Wei,Xiao, Yiting,Liu, Changwei,Xu, Shanghui,Yan, Xiaoli,Qin, Dawei
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Read Online
- Rational Design of Original Fused-Cycle Selective Inhibitors of Tryptophan 2,3-Dioxygenase
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Tryptophan 2,3-dioxygenase (TDO2) is a heme-containing enzyme constitutively expressed at high concentrations in the liver and responsible for l-tryptophan (l-Trp) homeostasis. Expression of TDO2 in cancer cells results in the inhibition of immune-mediated tumor rejection due to an enhancement of l-Trp catabolism via the kynurenine pathway. In the study herein, we disclose a new 6-(1H-indol-3-yl)-benzotriazole scaffold of TDO2 inhibitors developed through rational design, starting from existing inhibitors. Rigidification of the initial scaffold led to the synthesis of stable compounds displaying a nanomolar cellular potency and a better understanding of the structural modulations that can be accommodated inside the active site of hTDO2.
- Kozlova, Arina,Thabault, Léopold,Liberelle, Maxime,Klaessens, Simon,Prévost, Julien R. C.,Mathieu, Caroline,Pilotte, Luc,Stroobant, Vincent,Van Den Eynde, Beno?t,Frédérick, Rapha?l
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supporting information
p. 10967 - 10980
(2021/08/24)
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- QUINOXALINE DERIVATIVES
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The present invention relates to compounds according to general formula (I), which act as modulators of the glucocorticoid receptor and can be used in the treatment and/or prophylaxis of disorders which are at least partially mediated by the glucocorticoid receptor.
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Page/Page column 34
(2021/07/24)
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- Design, synthesis, and pharmacological profiling of cannabinoid 1 receptor allosteric modulators: Preclinical efficacy of C2-group GAT211 congeners for reducing intraocular pressure
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Allosteric modulators of cannabinoid 1 receptor (CB1R) show translational promise over orthosteric ligands due to their potential to elicit therapeutic benefit without cannabimimetic side effects. The prototypic 2-phenylindole CB1R allosteric modulator, GAT211 (1), demonstrates preclinical efficacy in various disease models. The limited systematic structure–activity relationship (SAR) data at the C2 position of the indole ring within GAT211 invites the opportunity for further modifications to improve GAT211′s pharmacological profile while serving to amplify and variegate this library of therapeutically attractive agents. These considerations prompted this focused SAR study in which we substituted the GAT211 C2-phenyl ring with heteroaromatic substituents. The synthesized GAT211 analogs were then evaluated in vitro as CB1R allosteric modulators in cAMP and β-arrestin2 assays with CP55,940 as the orthosteric ligand. Furan and thiophene rings (15c-f and 15m) were the best-tolerated substituents at the C2 position of GAT211 for engagement with human CB1R (hCB1R). The SAR around the novel ligands reported allowed direct experimental characterization of the interaction profile of that pharmacophore with its binding domain in functional, human CB1R, thus offering guidance for accessing subsequent-generation hCB1R allosteric modulators as potential therapeutics. The most potent analog, 15d, markedly promoted orthosteric ligand binding to hCB1R. Pharmacological profiling in the GTPγS and mouse vas deferens assays demonstrated that 15d behaves as a CB1R agonist-positive allosteric modulator (ago-PAM), as confirmed electrophysiologically in autoptic neurons. In vivo, 15d was efficacious as a topical agent that significantly reduced intraocular pressure (IOP) in the ocular normotensive murine model of glaucoma. Since elevated IOP is a decisive risk factor for glaucoma and attendant vision loss, our data support the proposition that the 2-phenylindole class of CB1R ago-PAMs has therapeutic potential for glaucoma and other diseases where potentiation of CB1R signaling may be therapeutic.
- Garai, Sumanta,Schaffer, Peter C.,Laprairie, Robert B.,Janero, David R.,Pertwee, Roger G.,Straiker, Alex,Thakur, Ganesh A.
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- Synthesis and anti-tumor activity of marine alkaloids
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Marine alkaloids were divided into five categories from the perspective of anti-tumor activity. The optimization process, chemical synthesis, anti-tumor activity evaluation and structure–activity relationship of various compounds were discussed.
- Chen, Guangying,Huang, Gangliang,Zhou, Shiyang
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- Electrochemical Rearrangement of 3-Hydroxyoxindoles into Benzoxazinones
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We report an unexpected rearrangement of 3-hydroxyoxindoles into benzoxazinones using electrochemistry. Our reaction employs mild and environmentally friendly conditions, and the benzoxazinone products are obtained in moderate to excellent yields. Mechanistic experiments suggest that a peroxide intermediate is likely involved.
- Kofink, Christiane,Maulide, Nuno,Pastor, Miryam,Vayer, Marie
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supporting information
(2022/01/15)
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- CONDENSED CYCLIC COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE INCLUDING THE SAME
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A condensed cyclic compound and an organic light-emitting device including the same, the condensed cyclic compound being represented by the following Formula 1:
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Paragraph 0412; 0414
(2020/02/29)
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- Predicting the Substrate Scope of the Flavin-Dependent Halogenase BrvH
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The recently described flavin-dependent halogenase BrvH is able to catalyse both the bromination and chlorination of indole, but shows significantly higher bromination activity. BrvH was annotated as a tryptophan halogenase, but does not accept tryptophan as a substrate. Its native substrate remains unknown. A predictive model with the data available for BrvH was analysed. A training set of compounds tested in vitro was docked into the active site of a complete protein model based on the X-ray structure of BrvH. The atoms not resolved experimentally were modelled by using molecular mechanics force fields to obtain this protein model. Furthermore, docking poses for the substrates and known non-substrates have been calculated. Parameters like distance, partial charge and hybridization state were analysed to derive rules for predicting activity. With this model for activity of the BrvH, a virtual screening suggested several structures for potential substrates. Some of the compounds preselected in this way were tested in vitro, and several could be verified as convertible substrates. Based on information on halogenated natural products, a new dataset was created to specifically search for natural products as substrates/products, and virtual screening in this database yielded further hits.
- Neubauer, Pia R.,Pienkny, Silke,Wessjohann, Ludger,Brandt, Wolfgang,Sewald, Norbert
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p. 3282 - 3288
(2020/08/05)
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- Flavin-Dependent Halogenases from Xanthomonas campestris pv. campestris B100 Prefer Bromination over Chlorination
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Flavin-dependent halogenases selectively introduce halogen substituents into (hetero-)aromatic substrates and require only molecular oxygen and halide salts for this regioselective oxidative CH-functionalization. Genomic analysis of Xanthomonas campestris pv. campestris B100 identified three novel putative members of this enzyme class. They were shown to introduce halogen substituents into, e. g., substituted indoles, while preferring bromide over chloride. (Figure presented.).
- Ismail, Mohamed,Frese, Marcel,Patschkowski, Thomas,Ortseifen, Vera,Niehaus, Karsten,Sewald, Norbert
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supporting information
p. 2475 - 2486
(2019/03/17)
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- Preparation method and purpose of pyrrolone BRD4 protein inhibitor
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The invention relates to the field of medicinal chemistry, in particular to pyrrolone derivatives, a preparation method of the pyrrolone derivatives, a pharmaceutical composition containing the compounds and medical purposes of the pharmaceutical composition, particularly an antitumor purpose of the pharmaceutical composition as a BRD4 protein inhibitor.
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Paragraph 0257; 0258; 0259
(2018/04/03)
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- A Versatile C–H Halogenation Strategy for Indole Derivatives under Electrochemical Catalyst- and Oxidant-Free Conditions
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Halogenated indoles are essential structural motifs in bioactive natural products. Reported herein is an economical and scalable electrochemical protocol for regioselective 3C–H halogenation of indole derivatives. This strategy provides access to a host of 3-iodo-, 3-bromo-, 3-chloro-, and 3-thiocyanoindole derivatives under mild conditions using inexpensive (pseudo)halide salts as the sole reagent. The optimized conditions do not require any supplementary electrolyte salts.
- Sun, Linhao,Zhang, Xing,Li, Zilong,Ma, Jimei,Zeng, Zhen,Jiang, Hong
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supporting information
p. 4949 - 4952
(2018/05/15)
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- PhI(OAc)2/NaX-mediated halogenation providing access to valuable synthons 3-haloindole derivatives
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This paper describes a mild phenyliodine diacetate mediated method for selective chlorination, bromination, and iodination of indole C-H bonds using sodium halide as a source for analogous halogenations. The combination of NaX and phenyliodine diacetate provides an invincible system for halogenation of indoles. This protocol was compatible with a wide array of indole substrates and provides straight forward access to potential halogenated arenes.
- Himabindu, Vittam,Parvathaneni, Sai Prathima,Rao, Vaidya Jayathirtha
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p. 18889 - 18893
(2018/11/27)
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- Synthesis of 2-arylindoles by Suzuki coupling reaction of 3-bromoindoles with hindered benzoboronic acids
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A new synthetic method for 2-arylindoles has been developed, the process through Suzuki coupling reaction of 3-bromoindoles with hindered boronic acid catalyzed by Pd(OAc)2/PCy3, and a series of 2-arylindoles have been synthesized in moderate to high yields.
- Yue, Guizhou,Wu, Yao,Wu, Caimei,Yin, Zhongqiong,Chen, Huabao,Wang, Xianxiang,Zhang, Zuming
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supporting information
p. 666 - 669
(2017/01/25)
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- Discovery of a potent protein kinase D inhibitor: insights in the binding mode of pyrazolo[3,4-d]pyrimidine analogues
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In this study, we set out to rationally optimize PKD inhibitors based on the pyrazolo[3,4-d]pyrimidine scaffold. The lead compound for this study was 1-NM-PP1, which was previously found by us and others to inhibit PKD. In our screening we identified one compound (3-IN-PP1) displaying a 10-fold increase in potency over 1-NM-PP1, opening new possibilities for specific protein kinase inhibitors for kinases that show sensitivity towards pyrazolo[3,4-d]pyrimidine derived compounds. Interestingly the observed SAR was not in complete agreement with the commonly observed binding mode where the pyrazolo[3,4-d]pyrimidine compounds are bound in a similar fashion as PKD's natural ligand ATP. Therefore we suggest an alternate binding mode where the compounds are flipped 180 degrees. This possible alternate binding mode for pyrazolo[3,4-d]pyrimidine based compounds could pave the way for a new class of specific protein kinase inhibitors for kinases sensitive towards pyrazolo[3,4-d]pyrmidines.
- Verschueren, Klaas,Cobbaut, Mathias,Demaerel, Joachim,Saadah, Lina,Voet, Arnout R. D.,Van Lint, Johan,De Borggraeve, Wim M.
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supporting information
p. 640 - 646
(2017/03/30)
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- Regioselective synthesis of 2,3′-biindoles mediated by an NBS-induced homo-coupling of indoles
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Mild conditions have been developed to achieve NBS-induced homodimerization of indole derivatives with excellent regioselectivity at 15 °C in high efficiency. This method provides a simple route to a 2,3′-linked biindolyl scaffold from the electron-rich to moderately electron-poor indoles. In addition, [3,2-a]carbazole derivatives can also be prepared through this method.
- Huang, Panpan,Peng, Xiangjun,Hu, Dan,Liao, Huiwu,Tang, Shaobin,Liu, Liangxian
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supporting information
p. 9622 - 9629
(2017/11/30)
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- Indium-Catalyzed Formal N-Arylation and N-Alkylation of Pyrroles with Amines
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Under indium Lewis acid catalysis, a nitrogen atom of N-unsubstituted pyrroles was replaced with a nitrogen atom of primary amines, thereby producing N-aryl- and N-alkylpyrroles. This system formally introducing such carbon frameworks to the pyrrole nitrogen atom shows unique selectivity: only the H?N(pyrrolyl) unit undergoes the N-arylation and N-alkylation even in the coexistence of a similar H?N(indolyl) part; and an aryl–halogen bond remains intact. These are clearly different from the typical method depending on the C?N(pyrrolyl) bond-forming reaction with organic halides as substrates. From a viewpoint of pyrrole N-protection–deprotection chemistry, worth noting is that a methyl group on the pyrrole nitrogen atom can be removed, albeit in a formal way. (Figure presented.).
- Yonekura, Kyohei,Oki, Kenji,Tsuchimoto, Teruhisa
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supporting information
p. 2895 - 2902
(2016/09/16)
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- Simple and efficient procedures for selective preparation of 3-haloindoles and 2,3-dihaloindoles by using 1,3-dibromo-5,5-dimethylhydantoin and 1,3-dichloro-5,5-dimethylhydantoin
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Simple and efficient synthetic procedures for the selective preparation of 3-bromo/3-chloroindoles and 2,3-dibromo/2,3-dichloroindoles by using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) and 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) were developed. Using 1,4-dioxane as the solvent, a variety of indoles, treated with 0.55 equiv DBDMH/DCDMH, afford the corresponding 3-bromo/3-chloroindoles selectively in 82-99% yield. In 1,2-dichloroethane (DCE), a series of 2,3-dichloro/2,3-dibromoindoles were selectively obtained in 84-95% yield by treating with DBDMH/DCDMH. All the processes do not need extra catalysts, dry solvents, or harsh reaction conditions.
- Yan, Jianwei,Ni, Tianjun,Yan, Fulin
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supporting information
p. 1096 - 1098
(2015/02/19)
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- Intramolecular Gold-Catalyzed and NaH-Supported Cyclization Reactions of N-Propargyl Indole Derivatives with Pyrazole and Pyrrole Rings: Synthesis of Pyrazolodiazepinoindole, Pyrazolopyrazinoindole, and Pyrrolopyrazinoindole
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Gold-catalyzed and NaH-supported intramolecular cyclization of N-propargyl indole derivatives with pyrazole and pyrrole units attached to indole is described. An efficient route to the synthesis of pyrazolodiazepinoindole, pyrazolopyrazinoindole, and pyrrolopyrazinoindole has been established. First, N-propargyl 2-(1H-pyrazol-5-yl)-1H-indole and 2-(1H-pyrrol-2-yl)-1H-indole were synthesized. Introduction of various substituents into the alkyne functionality was accomplished by Sonogashira cross-coupling reaction. Gold-catalyzed cyclization of pyrazoles having a terminal alkyne afforded the 6-exo-dig cyclization product. However, exclusive formation of 7-endo-dig cyclization products was observed with internal alkynes. On the other hand, cyclization with NaH only resulted in the formation of 6-exo-dig cyclization products regardless of the substitution of the alkyne functionality. Allenic intermediates were postulated for this outcome.
- Basceken, Sinan,Kaya, Serdal,Balci, Metin
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p. 12552 - 12561
(2016/01/09)
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- Total synthesis of asterredione
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The first total synthesis of asterredione was efficiently accomplished over five linear steps and in 21.5% overall yield. As the crucial step, the 2-quaternary 1,3-cyclopentenedione skeleton of asterredione was readily achieved using the Darzens/ring-expansion strategy developed in our laboratory. The structure of synthesized asterredione was fully confirmed by X-ray crystallography.
- Gai, Sinan,Zhang, Qing,Hu, Xiangdong
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supporting information
p. 2111 - 2114
(2014/04/03)
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- Total synthesis of carbazomycin G by a thermal ring expansion/self-redox reaction cascade
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The total synthesis of carbazomycin G (7) has been accomplished in six steps and 26% overall yield starting from commercially available materials. As an efficient access to the tricyclic skeleton of carbazomycins A-H, an interesting thermal ring expansion/self-redox reaction cascade of intermediate 11 has been developed in our study. The self-redox reaction of intermediate 10 can be readily accelerated in the presence of triethylamine, and a plausible reaction mechanism for this process has been proposed. Finally, the synthesis of carbazomycin G was completed by the widely applied regioselective methylation reaction. Copyright
- An, Yong,Wang, Yunxia,Hu, Xiangdong
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p. 3715 - 3718
(2014/06/23)
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- Synthesis and biological evaluation of analogs of the marine alkaloids granulatimide and isogranulatimide
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A series of pyrrolic analogs and two series of regioisomeric pyrazolic analogs of the marine alkaloids granulatimide and isogranulatimide were prepared. The synthesis of the two first ones was based on the condensation reaction of diversely 5-substituted 3-bromoindoles with pyrrole or pyrazole followed by addition of the intermediates on maleimide or dibromomaleimide, respectively, the so-obtained acyclic adducts being finally photocyclized to the desired analogs. Compounds of the last series were obtained by reacting different 5-substituted-indole-3-glyoxylates with N-Boc-pyrazole-3-acetamide and subsequent photochemical cyclization of the adducts. All the compounds were evaluated for their in vitro growth inhibitory properties toward eight cancer cell lines. Several compounds were also assayed for their ability to abrogate the G2-cell cycle checkpoint or to inhibit a panel of Ser/Thr kinases. Lastly, computer-assisted phase-contrast microscopy (quantitative videomicroscopy) revealed that the three most potent compounds (4a, 9a, 9e), with IC50 growth inhibitory concentrations ranging between 10 and 20 μM, displayed cytostatic, not cytotoxic, anticancer effects.
- Deslandes, Sebastien,Lamoral-Theys, Delphine,Frongia, Celine,Chassaing, Stefan,Bruyere, Celine,Lozach, Olivier,Meijer, Laurent,Ducommun, Bernard,Kiss, Robert,Delfourne, Evelyne
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scheme or table
p. 626 - 636
(2012/09/11)
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- Electrophilic bromination of alkenes, alkynes, and aromatic amines with iodic acid/potassium bromide under mild conditions
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Bromination of alkenes, alkynes, and aromatic amines has efficiently been carried out at room temperature in short reaction times using HIO 3/KBr in CH2Cl2/H2O (1:1) to prepare corresponding brominated compounds in excellent yields.
- Khazaei, Ardeshir,Zolfigol, Mohammad Ali,Kolvari, Eskandar,Koukabi, Nadiya,Soltani, Hamid,Bayani, Leyla Sharaf
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experimental part
p. 2954 - 2962
(2010/10/20)
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- Synthesis of two series of pyrazolic analogues of the marine alkaloids granulatimide and isogranulatimide as potent Checkpoint 1 kinase inhibitors
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Two series of regioisomeric pyrazolic analogues of the marine alkaloids granulatimide and isogranulatimide were prepared. The synthesis of the first series was based on the condensation reaction of diversely 5-substituted 3-bromoindoles with pyrazole followed by addition of the intermediates on dibromomaleimide, the so-obtained acyclic adducts being finally photochemically cyclised to the desired analogues. Compounds of the second series were obtained by reacting different 5-substituted-indole-3-glyoxylates with N-Boc-pyrazole-3-acetamide and subsequent photochemical cyclisation of the adducts.
- Deslandes, Sébastien,Chassaing, Stefan,Delfourne, Evelyne
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scheme or table
p. 5640 - 5642
(2010/11/18)
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- Elctrophilic bromination of alkenes, alkynes, and aromatic amines with potassium bromide/orthoperiodic acid under mild conditions
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Bromination of alkenes, alkynes, and aromatic amines has efficiently been carried out at room temperature in short reaction times using potassium bromide/orthoperiodic acid in dichloromethane-water (1:1) to prepare the corresponding bromo compounds with excellent yields.
- Khazaei, Ardeshir,Zolfigol, Mohammad Ali,Kolvari, Eskandar,Koukabi, Nadiya,Soltani, Hamid,Komaki, Fatemeh
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experimental part
p. 3672 - 3676
(2010/04/05)
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- Regioselective, photochemical bromination of aromatic compounds using N-bromosuccinimide
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Regioselective nuclear bromination of aromatic compounds is investigated with N-bromosuccinimide as the brominating agent under UV irradiation to afford the corresponding brominated compounds. The reaction proceeds at ambient temperature (30 ± 2 °C) without any catalyst. In most of the reactions, regioselectively mono-brominated products are obtained in good to high yields. The conversion and selectivity for bromination depend on the nature of the substituent on the aromatic ring.
- Chhattise, Prakash K.,Ramaswamy,Waghmode, Suresh B.
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p. 189 - 194
(2008/03/30)
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- A simple iodination protocol via in situ generated ICl using NaI/FeCl 3
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A novel iodination of silyl-enol ethers using hitherto unexplored NaI/FeCl3 system is reported. The procedure has been extended to the iodination of aromatic and hetero aromatic compounds.
- Mohanakrishnan, Arasambattu K.,Prakash, Chandran,Ramesh, Neelamegam
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p. 3242 - 3247
(2007/10/03)
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- Synthesis of isogranulatimide analogues possessing a pyrrole moiety instead of an imidazole heterocycle
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An efficient four step synthesis from commercial indoles of isogranulatimide analogues is reported. In the new compounds, the imidazole moiety is replaced by a pyrrole unit, the indole part is substituted or not in 5-position and the nitrogen of the imide moiety bears or not a methyl substituent.
- Hugon, Bernadette,Pfeiffer, Bruno,Renard, Pierre,Prudhomme, Michelle
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p. 3927 - 3930
(2007/10/03)
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- Regioselective one-pot bromination of aromatic amines
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(Matrix Presented) Treatment of aniline with n-butyllithium and then trimethyltin chloride gave the tin amide (PhNH-SnMe3) in situ. Without isolation of the tin amide reaction with bromine and workup with aqueous fluoride ion gave p-bromoaniline in 76% yield, with no dibromoaniline or o-bromoaniline. Application of this sequence to 11 different aromatic amines gave selective bromination in 36-91% yields, without formation of dibromides. This constitutes a good general method for the regioselective bromination of aromatic amines.
- Smith, Michael B.,Guo, Lisa,Okeyo, Sherrad,Stenzel, Jason,Yanella, James,LaChapelle, Eric
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p. 2321 - 2323
(2007/10/03)
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- BROMINATION OF KETONES AND PHENOLS WITH 4-(TRIBROMOMETHYL)QUINAZOLINE
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4-(Tribromomethyl)quinazoline, 1, in benzene behaves as a brominating agent towards ketones (in the enol form) and phenols.The reaction has the features of a polar reaction, notwithstanding the nature of the solvent.Ketones and phenols behave as nucleophiles, and attack a bromine atom of the brominating agent.
- Mencarelli, Paolo,Stegel, Franco
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- The Protection of Heterocyclic N-H Groups
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Pyrrole, indole, carbazole and imidazole have been protected as N- derivatives.Deprotection occured under mild conditions after quaternisation. 3-Bromoindole was prepared by bromination of the protected parent indole.
- Katritzky, Alan R.,Khan, Ghulam R.,Marson, Charles M.
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p. 641 - 644
(2007/10/02)
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- THE PREPARATION AND SPECTRAL CHARACTERIZATION OF 2-HALOINDOLES, 3-HALOINDOLES, AND 2,3-DIHALOINDOLES
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The preparation and properties of a series of 2- and 3-haloindoles and 2,3-dihaloindoles are described, and the mechanism of halogenation of 3-halo substituted indoles is briefly discussed.
- Brennan, Mary R.,Erickson, Karen L.,Szmalc, Frank S.,Tansey, Marilyn J.,Thornton, Janice M.
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p. 2879 - 2885
(2007/10/02)
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- A CONVENIENT CONVERSION OF INDOLES TO 3,3-DIBROMOOXINDOLES AND THEN TO ISATINS
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3-Bromoindoles, 3-unsubstituted indoles, or 3-formylindoles on treatment with NBS (2,3 or 4 molar equivalents, respectively) in t-butanol give 3,3-dibromooxindoles, and these readily yield the corresponding isatins on hydrolysis.
- Parrick, John,Yahya Arbaeyah,Jin, Yizun
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p. 3099 - 3100
(2007/10/02)
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- REACTION OF 3-INDOLYLPHENYLIODONIUM BETAINE WITH ELECTROPHILIC AGENTS
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3-Indolylphenyliodonium chloride and bromide, respectively, were obtained by the action of hydrochloric and hydrobromic acids on 3-indolylphenyliodonium betaine.Pyrolysis of the chloride leads to a mixture of 2- and 3-chloroindoles,while pyrolysis the bromine leads only to 3-bromoindole. 1-Benzyl-2-chloroindole is obtained in the reaction of the betaine with benzyl chloride.The betaine reacts with dimethylsulfate to give an iodonium salt, the reaction of wich with lithium chloride and ammonium chloride leads to 1-methyl-2-chloroindole.
- Budylin, V. A.,Ermolenko, M. S.,Chugtai, F. A.,Sharbatyan, P. A.,Kost, A. N.
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p. 1095 - 1097
(2007/10/02)
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