- Thieme Chemistry Journal Awardees - Where are they now? Catalytic transport with an amine carrier in a fluorous triphasic reaction
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Several aromatic aldehydes are transported by a fluorous amine from one organic phase through a fluorous phase to another organic phase. The derived imines react with phenylhydrazine to immobilize the transported product as a hydrazone and release the ami
- Montanari, Vittorio,Yu, Marvin S.,Curran, Dennis P.
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- Identification of novel 1,3-diaryl-1,2,4-triazole-capped histone deacetylase 6 inhibitors with potential anti-gastric cancer activity
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Histone deacetylase 6 (HDAC6) has emerged as a critical regulator of many cellular pathways in tumors due to its unique structure basis and abundant substrate types. Over the past few decades, the role played by HDAC6 inhibitors as anticancer agents has sparked great interest of biochemists worldwide. However, they were less reported for gastric cancer therapy. In this paper, with the help of bioisosteric replacement, in-house library screening, and lead optimization strategies, we designed, synthesized and verified a series of 1,3-diaryl-1,2,4-triazole-capped HDAC6 inhibitors with promising anti-gastric cancer activities. Amongst, compound 9r displayed the best inhibitory activity towards HDAC6 (IC50 = 30.6 nM), with 128-fold selectivity over HDAC1. Further BLI and CETSA assay proved the high affinity of 9r to HDAC6. In addition, 9r could dose-dependently upregulate the levels of acetylated α-tubulin, without significant effect on acetylated histone H3 in MGC803 cells. Besides, 9r exhibited potent antiproliferative effect on MGC803 cells, and promoted apoptosis and suppressed the metastasis without obvious toxicity, suggesting 9r would serve as a potential lead compound for the development of novel therapeutic agents of gastric cancer.
- Zhang, Xin-Hui,Kang, Hui-Qin,Tao, Yuan-Yuan,Li, Yi-Han,Zhao, Jun-Ru,Ya-Gao,Ma, Li-Ying,Liu, Hong-Min
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- Sequential [3+2] annulation reaction of prop-2-ynylsulfonium salts and hydrazonyl chlorides: Synthesis of pyrazoles containing functional motifs
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A novel sequential [3+2] annulation reaction has been developed using prop-2-ynylsulfonium salts and hydrazonyl chlorides, affording a series of pyrazoles with functional motifs that can be post modified in the preparation of various drugs or drug candidates. Further transformation and gram-scale operations could also be achieved efficiently. This journal is
- Jia, Tingting,Liu, Shourong,Shao, Jiaan,Shi, Tao,Wu, Zhaoxiao,Zeng, Linghui,Zhang, Chong,Zhang, Jiankang,Zhu, Huajian,Zhuang, Rangxiao
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supporting information
p. 8460 - 8463
(2021/09/08)
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- Transition-Metal-Free Coupling of 1,3-Dipoles and Boronic Acids as a Sustainable Approach to C?C Bond Formation
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The need for alternative, complementary approaches to enable C?C bond formation within organic chemistry is an on-going challenge in the area. Of particular relevance are transformations that proceed in the absence of transition-metal reagents. In the current study, we report a comprehensive investigation of the coupling of nitrile imines and aryl boronic acids as an approach towards sustainable C?C bond formation. In situ generation of the highly reactive 1,3-dipole facilitates a Petasis–Mannich-type coupling via a nucleophilic boronate complex. The introduction of hydrazonyl chlorides as a complementary nitrile imine source to the 2,5-tetrazoles previously reported by our laboratory further broadens the scope of the approach. Additionally, we exemplify for the first time the extension of this protocol into another 1,3-dipole, through the synthesis of aryl ketone oximes from aryl boronic acids and nitrile N-oxides.
- Livingstone, Keith,Bertrand, Sophie,Kennedy, Alan R.,Jamieson, Craig
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supporting information
p. 10591 - 10597
(2020/07/25)
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- Experimental and quantum chemical studies of the structural and spectral properties of novel diazenyl formazans
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A new series of 3-(p-substitutedphenyl)-5-phenyl-1-(4-phenyldiazenyl)phenylformazans were synthesized by coupling p-substituted phenyl or pyridinylhydrazones with p-aminoazobenzene diazonium chloride. All compounds were characterized by FT-IR, UV–Vis, 1H NMR, and 13C NMR spectroscopic techniques, and HR-MS. DFT was used to calculate the molecular structures and 1H and 13C chemical shift values of the synthesized compounds with PBE1PBE functional and 6-311G(2d,2p)basis set combination. The IR spectra of the novel formazans were calculated using DFT at PBE1PBE/6-311G(d,p)level of theory. The electronic absorption spectra of the optimized structures were evaluated by TD-DFT method at PBE1PBE/6-311G(2d,2p)level of theory. The absorption spectra of the synthesized diazenyl formazans were investigated in three different solvents. A good correlation was established between the experimental data and calculated results.
- Tezcan, Habibe,?en?z, Hülya,Tokay, Nesrin
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p. 171 - 183
(2019/04/29)
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- Synthesis of hybrid polycycles containing fused hydroxy benzofuran and 1H-indazoles via a domino cyclization reaction
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A stoichiometry controlled domino cyclization reaction of hydrazone and p-benzoquinone to an angularly fused 3H-benzofuro[3,2-e]indazole core with an embedded oxygenated dibenzofuran framework under mild reaction conditions is disclosed. The reaction involves palladium catalyzed 5-hydroxy-1H-indazole formation followed by TFA mediated [3+2] annulation between the in situ formed 5-hydroxy-1H-indazole and p-benzoquinone. The developed method is attractive because of the concomitant formation of two heterocyclic rings with consecutive multiple bond forming events that include two C-C, one C-N and one C-O bonds. Spectroscopic and theoretical studies of the blue emissive benzofuroindazole derivatives have also been described.
- Janardhanan, Jith C.,James, Kiran,Puthuvakkal, Anisha,Bhaskaran, Rasmi P.,Suresh, Cherumuttathu H.,Praveen, Vakayil K.,Manoj, Narayanapillai,Babu, Beneesh P.
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p. 10166 - 10175
(2019/07/03)
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- Stereospecific copper(II)-catalyzed tandem ring opening/oxidative alkylation of donor-acceptor cyclopropanes with hydrazones: Synthesis of tetrahydropyridazines
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Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
- Mishra, Manmath,De, Pinaki Bhusan,Pradhan, Sourav,Punniyamurthy, Tharmalingam
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p. 10901 - 10910
(2019/09/13)
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- The use of enaminones and enamines as effective synthons for MSA-catalyzed regioselective synthesis of 1,3,4-tri- And 1,3,4,5-tetrasubstituted pyrazoles
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In the present work, an efficient regioselective synthesis of 1,3,4-tri- and 1,3,4,5-tetrasubstituted pyrazoles via a methanesulfonic acid (MSA)-catalyzed reaction of hydrazones with enaminones or enamines is reported. Mechanistically, the formation of the title compounds involves the [2+3] cycloaddition of hydrazones with enaminones or enamines followed by aromatization with acid and oxygen. This convenient method under mild conditions with various hydrazones, enaminones, and enamines was well-tolerated to afford products in good to excellent yields. Compared with the literature methods, this strategy has advantages such as materials that are available economically, metal-free catalysis, excellent regioselectivity, and high efficiency.
- Duan, Liancheng,Zhou, Hui,Gu, Yucheng,Gong, Ping,Qin, Mingze
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supporting information
p. 16131 - 16137
(2019/11/03)
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- Fe+3-montmorillonite K10 as an Efficient Reusable Heterogeneous Catalyst for the Grind Mediated Synthesis of 14-aryl-14H-dibenzo [a,j]xanthenes
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Background: Xanthenes are an important class of organic compounds and have also received significant attention due to their wide range of pharmacological activities such as antibacterial, antiviral, antiinflammatory activities, antagonists for the paralyzing action of zoxazolamine and efficiency in photodynamic therapy, a well-known method for controlling the localized tumors. Natural sources are also rich of xanthene compounds. Popularly known pigments, santalin have been isolated from plant species. Furthermore, these compounds can be emerged as pH-sensitive fluorescent materials for visualization of biomolecules, in laser technologies and as dyes. There are several reports in the literature for the synthesis of xanthenes such as alkylations of heteroatoms, cyclodehydrations, cyclocondensations between 2-hydroxyaromatic aldehydes and 2- tetralone, trapping of benzynes by phenols and intramolecular phenyl-carbonyl coupling reactions of benzaldehydes and acetophenones bearing tethered carbonyl chains in the presence of hexamethylphosphoramide and SmI2. Other methods for the synthesis of xanthenes include the reaction of formamide with β-naphthol, carbon monoxide, and 1- hydroxymethyl-naphthalen-2-ol. Methods: procedure a: A mixture of substituted benzaldehyde, 2-naphtol and Fe+3-montmorillonite K10 was mixed. After completion of the reaction, the product was solved in CHCl3 (3×10 mL) and insoluble catalyst was removed by filtration. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. procedure b: A mixture of substituted benzaldehyde, phenylhydrazine and Fe+3-montmorillonite K10 were added to a mortar and the mixture was pulverized with a pestle. After completion of the reaction, 2-naphtol was added to the consulting mixture and pulverized with a pestle. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. Results: As part of our going interest for the development of efficient and environmentally friendly procedures for the synthesis of heterocyclic and pharmaceutical compounds, we wish to report the first grind mediated synthesis of some derivatives of xanthenes using catalytic amount of Fe+3-montmotillonite. Conclusion: In conclusion, we have investigated the Fe+3-montmorillonite K10 under grinding as a mild and efficient catalyst for the synthesis of substituted 14-aryl-14H-dibenzo [a,j]xanthenes. The remarkable advantages offered by this method are: catalyst is inexpensive, non-toxic, easy handling and reusability, simple work-up procedure, short reaction time, high yields of product with better purity and green aspect by avoiding toxic catalyst and hazardous solvent.
- Fekri, Leila Z.,Nikpassand, Mohammad,Fard, Hajar S.,Marvi, Omid
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p. 135 - 142
(2016/03/01)
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- Radical Addition of Hydrazones by α-Bromo Ketones to Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis
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A novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to excellent yields. This efficient strategy under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles.
- Fan, Xiu-Wei,Lei, Tao,Zhou, Chao,Meng, Qing-Yuan,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
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p. 7127 - 7133
(2016/08/30)
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- A novel chemoselective synthesis of 3H-spiro[isobenzofuran-1,3'-pyrazole] derivatives by oxidative cleavage of their corresponding dihydroindeno[1,2-c]pyrazoles
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Abstract This paper reports a new and simple procedure for the synthesis of 3H-spiro[isobenzofuran-1,3'-pyrazole] derivatives by reacting 1-benzylidene-2-phenylhydrazine derivatives with ninhydrin in acetic acid medium at room temperature followed by oxidative cleavage of their corresponding dihydroindeno[1,2-c]pyrazoles. 1-Benzylidene-2-phenylhydrazine derivatives were prepared via the reaction between phenylhydrazine and benzaldehyde derivatives. Easy procedure, mild reaction conditions, high yields in short reaction times, availability of starting materials, and no formation of by-product are the advantages of this approach.
- Mohammadizadeh, Mohammad Reza,Basti, Fatemeh
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p. 1171 - 1176
(2015/06/02)
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- Room temperature ionic liquid choline chloride-oxalic acid: A versatile catalyst for acid-catalyzed transformation in organic reactions
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An efficient and facile synthesis of hydrazones, bis(indolyl)methanes and bis(4-hydroxycoumarin)methanes is facilitated by room temperature ionic liquid choline chloride-oxalic acid (ChCl:Ox). ChCl:Ox (10 mol%) efficiently catalyzes condensation of aldehydes with phenylhydrazine giving corresponding hydrazones in high yield (92-96%) within short reaction time of 3-5 min. Electrophilic cyclization reaction of indole and 4-hydroxy coumarin with aromatic aldehyde was effectively promoted by 30 mol% of ChCl:Ox giving corresponding bis(indolyl)arylmethanes and bis (4-hydroxycoumarin)methanes in good yield at room temperature. Procedure is very simple, solvent free and completely eliminates use of toxic acid catalyst. ChCl:Ox is biodegradable, can be recycled and reused without the loss of efficiency with respect to yield.
- Yadav, Urmiladevi Narad,Shankarling, Ganapati Subray
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p. 137 - 141
(2014/01/17)
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- Diaryl hydrazones as multifunctional inhibitors of amyloid self-assembly
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The design and application of an effective, new class of multifunctional small molecule inhibitors of amyloid self-assembly are described. Several compounds based on the diaryl hydrazone scaffold were designed. Forty-four substituted derivatives of this core structure were synthesized using a variety of benzaldehydes and phenylhydrazines and characterized. The inhibitor candidates were evaluated in multiple assays, including the inhibition of amyloid β (Aβ) fibrillogenesis and oligomer formation and the reverse processes, the disassembly of preformed fibrils and oligomers. Because the structure of the hydrazone-based inhibitors mimics the redox features of the antioxidant resveratrol, the radical scavenging effect of the compounds was evaluated by colorimetric assays against 2,2-diphenyl-1-picrylhydrazyl and superoxide radicals. The hydrazone scaffold was active in all of the different assays. The structure-activity relationship revealed that the substituents on the aromatic rings had a considerable effect on the overall activity of the compounds. The inhibitors showed strong activity in fibrillogenesis inhibition and disassembly, and even greater potency in the inhibition of oligomer formation and oligomer disassembly. Supporting the quantitative fluorometric and colorimetric assays, size exclusion chromatographic studies indicated that the best compounds practically eliminated or substantially inhibited the formation of soluble, aggregated Aβ species, as well. Atomic force microscopy was also applied to monitor the morphology of Aβ deposits. The compounds also possessed the predicted antioxidant properties; approximately 30% of the synthesized compounds showed a radical scavenging effect equal to or better than that of resveratrol or ascorbic acid.
- T?r?k, Béla,Sood, Abha,Bag, Seema,Tulsan, Rekha,Ghosh, Sanjukta,Borkin, Dmitry,Kennedy, Arleen R.,Melanson, Michelle,Madden, Richard,Zhou, Weihong,Levine, Harry,T?r?k, Marianna
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p. 1137 - 1148
(2013/08/24)
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- Synthesis and stereochemistry of some novel dihydropyrrolo[3,4-c]pyrazoles
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Eleven novel dihydropyrrolo[3,4-c]pyrazole derivatives were obtained by the reaction of chiral (1R)-N-(1-phenylethyl)maleimide and C,N-aryl-substituted nitril-imines. The reaction afforded the cycloadducts as a regioisomeric mixture which can be separable in some cases. The structure and stereochemistry of cycloadducts were assigned on the basis of infrared (IR), 1H and 13C nuclear magnetic resonance (NMR), mass and X-ray spectra, optical rotation measurements, and CHN analyses.
- Dueruest, Yasar,Yildirm, Muhammet,Fronczek, Chris F.,Fronczek, Frank R.
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scheme or table
p. 127 - 138
(2012/07/27)
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- Copper-mediated synthesis of substituted 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles via C-H functionalization/C-N/C-O bond formation
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An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.
- Guru, Murali Mohan,Ali, Md Ashif,Punniyamurthy, Tharmalingam
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p. 5295 - 5308
(2011/08/05)
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- Polystyrene sulfonic acid catalyzed greener synthesis of hydrazones in aqueous medium using microwaves
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An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any
- Polshettiwar, Vivek,Varma, Rajender S.
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p. 5649 - 5652
(2008/02/10)
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