- Convenient synthesis of flavanone derivatives via oxa-Michael addition using catalytic amount of aqueous cesium fluoride
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A total of 36 flavanones, which included polycyclic aromatic and heterocyclic rings, were readily synthesized via oxa-Michael addition from the corresponding hydroxychalcones with a catalytic amount of aqueous cesium fluoride solution under mild conditions. This method could be applied to the scalable synthesis of eriodictyol as a known potent inhibitor of the SARS-CoV-2 spike protein.
- Miura, Motofumi,Shigematsu, Karin,Toriyama, Masaharu,Motohashi, Shigeyasu
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supporting information
(2021/10/25)
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- B regioselective and chemoselective biotransformation of 2′-hydroxychalcone derivatives by marine-derived fungi
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Eight fungal strains (Penicillium raistrickii CBMAI 931, Cladosporium sp. CBMAI 1237, Aspergillus sydowii CBMAI 935, Penicillium oxalicum CBMAI 1996, Penicillium citrinum CBMAI 1186, Mucor racemosus CBMAI 847, Westerdykella sp. CBMAI 1679, and Aspergillus sclerotiorum CBMAI 849) mediated the biotransformation of the 2′-hydroxychalcone 1a. The main products obtained were from hydrogenation, hydroxylation, and cyclization reactions. Penicillium raistrickii CBMAI 931 catalyzed the chemoselective reduction of 1a to produce 2′-hydroxydihydrochalcone 2a (72%) in 7 days of incubation in phosphate buffer (pH 7). Aspergillus sydowii CBMAI 935 promoted the hydroxylation of 1a to yield 2′,4-dihydroxy-dihydrochalcone 5a (c = 42%) in 7 days of incubation in phosphate buffer (pH 8). The reaction using P. citrinum CBMAI 1186 and M. racemosus CBMAI 847 presented main cyclization products in phosphate buffer (pH 8), but the reactions with these fungi did not present enantioselectivity. Marine-derived fungi were effective and versatile biocatalysts for biotransformation of the 2′-hydroxychalcones yielding different products according to the conditions and microorganism used.
- Nitschke, Marcia,Porto, André Luiz Meleiro,de Matos, Iara Lisboa
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- Divergent synthesis of flavones and flavanones from 2′-hydroxydihydrochalconesviapalladium(ii)-catalyzed oxidative cyclization
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Divergent and versatile synthetic routes to flavones and flavanonesviaefficient Pd(ii) catalysis are disclosed. These Pd(ii) catalyses expediently provide a variety of flavones and flavanones from 2′-hydroxydihydrochalcones as common intermediates, depending on oxidants and additives,viadiscriminate oxidative cyclization sequences involving dehydrogenation, respectively, in a highly atom-economic manner.
- Son, Seung Hwan,Cho, Yang Yil,Yoo, Hyung-Seok,Lee, Soo Jin,Kim, Young Min,Jang, Hyu Jeong,Kim, Dong Hwan,Shin, Jeong-Won,Kim, Nam-Jung
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p. 14000 - 14006
(2021/04/22)
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- Stereoselective reduction of flavanones by marine-derived fungi
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Biotransformation is an alternative with great potential to modify the structures of natural and synthetic flavonoids. Therefore, the bioreduction of synthetic halogenated flavanones employing marine-derived fungi was described, aiming the synthesis of flavan-4-ols 3a-g with high enantiomeric excesses (ee) of both cis- and trans-diastereoisomers (up to >99% ee). Ten strains were screened for reduction of flavanone 2a in liquid medium and in phosphate buffer solution. The most selective strains Cladosporium sp. CBMAI 1237 and Acremonium sp. CBMAI1676 were employed for reduction of flavanones 2a-g. The fungus Cladosporium sp. CBMAI 1237 presented yields of 72–87% with 0–64% ee cis and 0–30% ee trans with diastereoisomeric ratio (dr) from 52:48 to 64:36 (cis:trans). Whereas Acremonium sp. CBMAI 1676 resulted in 31% yield with 77–99% ee of the cis and 95–99% ee of the trans-diastereoisomers 3a-g with a dr from 54:46 to 96:4 (cis:trans). To our knowledge, this is the first report of the brominated flavon-4-ols 3e and 3f. The use of fungi, with emphasis for these marine-derived strains, is an interesting approach for enantioselective reduction of halogenated flavanones. Therefore, this strategy can be explored to obtain enantioenriched compounds with biological activities.
- Birolli, Willian G.,Nitschke, Marcia,Porto, André Luiz M.,Santos, Darlisson de A.,de Matos, Iara L.
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- Glycolytic inhibition and antidiabetic activity on synthesized flavanone scaffolds with computer aided drug designing tools
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Background: Diabetes mellitus is a challengeable metabolic disorder that leads to a group of complications when the HbA1c level is not maintained. Most of the existing drugs avail-able in the market in long-term use may lead to serious adverse effects. He
- Kiruthiga, Natarajan,Saravanan, Govindaraj,Selvinthanuja, Chellappa,Sivakumar, Thangavel,Srinivasan, Kulandaivel
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p. 574 - 592
(2021/09/30)
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- Synthesis and cytotoxicity of novel (E)-2-phenylchroman-4-one-O-((1-substituted-1H-1,2,3-triazol-4-yl)methyl) oxime derivatives
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A series of new flavanone-triazole hybrids (7a–m) were synthesized from flavanone oximes (6a–c) via multistep synthetic strategy, involving Cu (I) catalyzed azide, alkyne 1,3-dipolar cycloaddition by Click reaction. All the synthesized compounds were tested for their cytotoxicity against HCT-15, HeLa, NCI-H522, and HEK-293 (normal cell line) cell lines. Compounds 6a, 7a, 7b, 7d, 7e, 7j, and 7m showed the significant cytotoxicity, wherein compound 7b showed potential cytotoxicity against NCI-H522 cell line and compounds 6a and 7a were offensive with HEK-293 in their toxicity profile.
- Gutam, Madhu,Mokenapelli, Sudhakar,Yerrabelli, Jayaprakash Rao,Banerjee, Somesh,Roy, Partha,Chitneni, Prasad Rao
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p. 1883 - 1891
(2020/05/13)
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- Not only AIE: Light-sensitivity of 4-dimethylamino-2′-hydroxychalcones beneficial to highly efficient photochemical synthesis of 4′-dimethylaminoflavanones
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4-dimethylamino-2′-hydroxychalcone in crystals is well known for its aggregation induced emission (AIE) in the red region of spectrum. We however observe that in liquid solutions this dye and its analogues undergo reversible wavelength-dependent light-induced cyclization to the flavanone derivatives. Special care thus should be taken when this compound is used for optoelectronic applications requiring high purity, especially via solution-processed methods. The discussed intramolecular cyclization proceeds faster in nonpolar medium and is quenched completely in the presence of protic solvents or via formation of aggregates in crystal phase. In spite of that quantum yield of a single photoinduced transformation does not exceed 1%, continuous irradiation affords 92% of product which makes it the most efficient preparation route for 4′-dimethylminoflavanone and its derivatives among the ones reported before. According to the DFT and TDDFT calculations supported by the experimentally investigated spectral features, the mechanism of photoinduced formation of a 4′-dimethylaminoflavanone involves several transformations: excited state intramolecular proton transfer (ESIPT), excited and ground state rotational isomerization from s-trans to s-cis isomer, cyclization and enol-keto tautomerization via proton transfer in the ground state.
- Bojarski, Piotr,Kubicki, Aleksander,Mońka, Michal,Serdiuk, Illia E.
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- Organocatalytic Approach for Assembling Flavanones via a Cascade 1,4-Conjugate Addition/oxa-Michael Addition between Propargylamines with Water
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A DBU-catalyzed one-pot cascade reaction of propargylamines and water for the synthesis of flavanones has been developed. This process proceeds via a sequence of 1,4-conjugate addition of water to alkynyl o-quinone methide (o-AQM), followed by the alkyne-allene isomerization and subsequent intramolecular oxa-Michael addition. This strategy provides a convenient method for accessing a broad range of flavanones in good to excellent yields with good functional-group tolerance, in particular, the reactive halo functional groups.
- He, Xinwei,He, Xinwei,Xie, Mengqing,Li, Ruxue,Choy, Pui Ying,Tang, Qiang,Shang, Yongjia,Kwong, Fuk Yee
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p. 4306 - 4310
(2020/06/05)
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- Synthesis and hplc-ecd study of cytostatic condensed o,n-heterocycles obtained from 3-aminoflavanones
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Racemic chiral O,N-heterocycles containing 2-arylchroman or 2-aryl-2H-chromene subunit condensed with morpholine, thiazole, or pyrrole moieties at the C-3-C-4 bond were synthesized with various substitution patterns of the aryl group by the cyclization of cis- or trans-3- aminoflavanone analogues. The 3-aminoflavanone precursors were obtained in a Neber rearrangement of oxime tosylates of flavanones, which provided the trans diastereomer as the major product and enabled the isolation of both the cis- and trans-diastereomers. The cis- and transaminoflavanones were utilized to prepare three diastereomers of 5-aryl-chromeno[4,3- b][1,4]oxazines. Antiproliferative activity of the condensed heterocycles and precursors was evaluated against A2780 and WM35 cancer cell lines. For a 3-(N-chloroacetylamino)-flavan-4-ol derivative, showing structural analogy with acyclic acid ceramidase inhibitors, 0.15 μM, 3.50 μM, and 6.06 μM IC50 values were measured against A2780, WM35, and HaCat cell lines, and apoptotic mechanism was confirmed. Low micromolar IC50 values down to 2.14 μM were identified for the thiazole- and pyrrole-condensed 2H-chromene derivatives. Enantiomers of the condensed heterocycles were separated by HPLC using chiral stationary phase, HPLC-ECD spectra were recorded and TDDFT-ECD calculations were performed to determine the absolute configuration and solution conformation. Characteristic ECD transitions of the separated enantiomers were correlated with the absolute configuration and effect of substitution pattern on the HPLC elution order was determined.
- Szappanos,Mándi, Attila,Gulácsi, Katalin,Lisztes, Erika,István Tóth, Balázs,Bíró, Tamás,Kónya-ábrahám, Anita,Kiss-Szikszai, Attila,Bényei, Attila,Antus, Sándor,Kurtán, Tibor
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- Enzyme-assisted cyclization of chalcones to flavanones
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Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.
- Alonso, Mariana Macías,Boluda, Carlos José,Barajas, Gabriela Díaz,Sánchez, Nallely Caldera,Córdova-Guerrero, Iván,Marrero, Joaquín González
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p. 926 - 931
(2020/12/23)
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- Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
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A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92percent.
- Cho, Yang Yil,Jang, Hyu Jeong,Kim, Dong Hwan,Kim, Nam Yong,Kim, Nam-Jung,Kim, Young Min,Lee, Soo Jin,Lee, Yong Sup,Park, Boyoung Y.,Son, Seung Hwan,Yoo, Hyung-Seok
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p. 10012 - 10023
(2019/08/30)
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- Discovery of a Prenylated Flavonol Derivative as a Pin1 Inhibitor to Suppress Hepatocellular Carcinoma by Modulating MicroRNA Biogenesis
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Peptidyl-prolyl cis-trans isomerase Pin1 plays a crucial role in the development of human cancers. Recently, we have disclosed that Pin1 regulates the biogenesis of miRNA, which is aberrantly expressed in HCC and promotes HCC progression, indicating the therapeutic role of Pin1 in HCC therapy. Here, 7-(benzyloxy)-3,5-dihydroxy-2-(4-methoxyphenyl)-8-(3-methylbut-2-en-1-yl)-4H-chromen-4-one (AF-39) was identified as a novel Pin1 inhibitor. Biochemical tests indicate that AF-39 potently inhibits Pin1 activity with an IC50 values of 1.008 μm, and also displays high selectivity for Pin1 among peptidyl prolyl isomerases. Furthermore, AF-39 significantly suppresses cell proliferation of HCC cells in a dose- and time-dependent manner. Mechanistically, AF-39 regulates the subcellular distribution of XPO5 and increases miRNAs biogenesis in HCC cells. This work provides a promising lead compound for HCC treatment, highlighting the therapeutic potential of miRNA-based therapy against human cancer.
- Zheng, Yuanyuan,Pu, Wenchen,Li, Jiao,Shen, Xianyan,Zhou, Qiang,Fan, Xin,Yang, Sheng-Yong,Yu, Yamei,Chen, Qiang,Wang, Chun,Wu, Xin,Peng, Yong
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supporting information
p. 130 - 134
(2018/11/30)
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- Synthesis and kinetic investigations for the isomerization process of 2–hydroxy chalcone derivatives
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The wide biological activities of flavanones are mainly depends on their physical and chemical properties, thus a number of substituted 2-Hydroxy chalcones have been synthesized, and their isomerization to their corresponding flavanones was studied. In order to determine the rate constant, kinetic experiments were performed using HPLC technique in (9:1) (CH3CN:H2O) medium at different temperature (298-318) K. The obtained results were interpreted by four steps mechanism, which considered the existence of phenoxide ion as the key intermediate. This study performed with a pseudo first order (reaction in which the rate for the studied compounds follow the sequence 5 > 2 > 1 > 4 > 3, the activation energy have the same sequence for these compounds .The effect of substituents on the rate showed that electronic and steric factors play reasonable role on the stability of the product .
- Shareef, Omar A.,Said, Said A.,Abdulrazaq, Ali Y.
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p. 1046 - 1054
(2020/01/09)
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- Water-mediated phosphorylative cyclodehydrogenation: An efficient preparation of flavones and flavanones
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A new synthetic strategy utilizing POCl3-water for the conversion of 2′-hydroxychalcones to flavanones and flavones has been developed. The reagent efficiently promoted one-pot conversion of 2′-hydroxychalcones to flavones through flavanones involving cyclization and oxidative dehydrogenation. By changing the stoichiometery of the reagents, the reaction can be tuned to generate either flavanone or flavone. The developed protocol was found to be applicable for a variety of 2′-hydroxychalcones.
- Vimal, Manorama,Pathak, Uma,Halve, Anand Kumar
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supporting information
p. 2805 - 2814
(2019/08/12)
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- Glycosylation of methoxylated flavonoids in the cultures of isaria fumosorosea KCH J2
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Flavonoids are widely described plant secondary metabolites with high and diverse pro-health properties. In nature, they occur mostly in the form of glycosides. Our research showed that an excellent way to obtain the sugar derivatives of flavonoids is thr
- Dymarska, Monika,Janeczko, Tomasz,Kostrzewa-Sus?ow, Edyta
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- Synthesis of pyrazole-substituted chromene analogues with selective anti-leukemic activity
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We report design and synthesis of a series of flavanone/chromene derivatives containing pyrazoles 6a–6h and 8a–8e with potent anti-leukemic activity. Anti-leukemic activity of novel flavanone derivatives was tested using the K562 cell line. The parental flavanone was selected as the reference compound in identification of analogues with superior anti-leukemic activity. More than two-thirds of the derivatives displayed higher activity than the initial flavanone. Positions of substituents that promoted anti-leukemic activity were identified on both the chromene and pyrazole fragments. Compounds 6b and 6c showed the highest activity against K562 cell line, with IC50 values 3.0 and 0.5 μM respectively. Notably, compounds 6b and 6c displayed very high selectivity in inhibition of leukemic cells (K562) but not of healthy HEK293 cells or solid cancer cell lines HeLa, MCF7 and BT474. Moreover, both the 6b and 6c compounds were predicted to have good ADME properties.
- Madhu,Sudhakar,Santosh Kumar,Rajashekher Reddy,Sravani,Ramakrishna,Prasad Rao, Ch.
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p. 2421 - 2428
(2017/11/24)
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- Palladium-Catalyzed [3+3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji–Trost Reaction
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Vinyl chromium(0) Fischer carbene complexes were employed as the source of π-allylic palladium species for catalytic [3+3] annulation under palladium catalysis. Mechanistically, this transformation is proposed to involve carbene migratory insertion and intramolecular Tsuji–Trost reaction as the key steps. Substituted six-membered heterocyclic flavonones and quinolines are obtained, depending on the nucleophilic functional group on the coupling partners.
- Wang, Kang,Ping, Yifan,Chang, Taiwei,Wang, Jianbo
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supporting information
p. 13140 - 13144
(2017/10/11)
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- Guanidino-graphene catalysed synthesis of flavones via Aldol-Michael-oxidation
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Guanidino-graphene has been synthesized by the reaction of bromoamine with reduced graphene oxide and characterized by FT-IR, Raman, TGA, powder XRD, TEM, SEM, and zeta potential. It is a cheap, heterogeneous and environmentally benign solid base catalyst used for cascade Aldol-Michael-oxidation in the synthesis of chalcone, flavonoids.
- Mishra, Sweta,Arora, Smriti,Nagpal, Ritika,Chauhan, Shive Murat Singh
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p. 2525 - 2530
(2017/03/09)
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- Synthesis, crystal structure and antitumour activity evaluation of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives
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A series of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives were synthesised through Knoevenagel condensation of substituted flavanones with thiazolidine-2,4-dione in ethanol in the presence of piperidine. The mechanism of the reaction was proposed. All synthesised compounds were characterised by IR, 1H NMR, 13C NMR, HRMS, and elemental analysis. The structure of 2-(3-chlorophenyl)-1H-thieno[2,3-c]chromen-4(2H)-one was confirmed by a single crystal X-ray diffraction analysis. A preliminary antitumour screening showed that 2-(2-fluorophenyl)-1H-thieno [2,3-c]chromen-4(2H)-one had moderate to good activity against A549, BGC-823, HCT116 and MDA-MB-453 cancer cell lines, and 2-(3,4-dimethoxyphenyl)-1H-thieno[2,3-c]chromen-4(2H)-one displayed similar activity against these four kinds of cancer cells compared with the reference drug.
- Yu, Huchang,Li, Yan,Feng, Zhiyuan,Jiang, Hongwu,Zhao, Yinglan,Luo, Youfu,Huang, Wencai,Li, Zicheng
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- Efficient Access to Chromeno[4,3- b ]quinolines Related to Dependensin
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We report a robust synthesis of novel chromeno[4,3- b ]quinoline derivatives structurally similar to the natural product dependensin. The target compounds are accessed through the acid-catalysed condensation of 2-aminoacetophenones or 2-aminochalcones with substituted flavanones, which are in turn obtained from 2-hydroxyacetophenones and benzaldehydes.
- Dobrowolski, Jeremy C.,Fraser, Benjamin H.,Bhadbhade, Mohan,Black, David Stc.,Kumar, Naresh
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p. 1979 - 1983
(2017/09/13)
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- An efficient synthesis of flavanones and their docking studies with aldose reductase
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A series of flavanone derivatives have been synthesized from 2-hydroxy acetophenone and benzaldehyde using fused calcium chloride in good to moderate yields, and their in vitro aldose reductase inhibitory activity has been tested on aldose reductase purified enzyme from Bovine lens. Most of the synthesized compounds exhibited potent aldose reductase inhibitory activity, and the obtained results are supported by the docking studies. Among the tested derivatives, 2, 3, 4-methoxy derivative 19 (IC50 5.88 ± 0.03 μM) exhibited the highest inhibitory activity whereas 2-methoxy derivative 12 showed the lowest, and the remaining compounds exhibited moderate activity with IC50 in the range of 6.09–7.89 μM. The spatial configuration of the most active derivative 19 was compared with pharmacophore requirements of the aldose reductase inhibitor site using a molecular modeling system.
- Kondhare,Gyananath,Tamboli, Yasinalli,Kumbhar, Santosh S.,Choudhari, Prafulla B.,Bhatia, Manish S.,Zubaidha
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p. 987 - 998
(2017/04/14)
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- Synthesis, stereochemistry and antimicrobial activity of some novel flavanone-hydrazono-thiazolidin-4-ones from flavanones
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The synthesis of four novel compounds, (i) E-2-{[2-(4-methoxyphenyl)chroman-E-4-ylidene]hydrazono}thiazolidin-4-one (4a), (ii) E-2-{[2-(4-methoxyphenyl)chroman-Z-4-ylidene]hydrazono}thiazolidin-4-one (5a), (iii) E-2-{[2-(phenyl)chroman-E-4-ylidene]hydrazo
- Mukhtar, Sayeed,Al-Ahmdi, Mohammed Issa,Parveen, Humaira
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p. 2589 - 2595
(2016/10/17)
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- Convenient and highly efficient routes to 2 H-chromene and 4-chromanone derivatives: Iodine-promoted and p-toluenesulfonic acid catalyzed cascade cyclizations of propynols
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A convenient strategy is presented for the easy preparation of a series of 2 H-chromenes under mild conditions through iodocyclization of readily accessible propynols. In addition, various 4-chromanones can be synthesized through a p-toluenesulfonic acid catalyzed cascade cyclization with high efficiency (yields up to 99%). Our developed reaction systems are proven to have good functional-group applicability and can be scaled up to gram quantities in satisfactory yields. These systems also provide a new synthetic strategy for two types of important flavonoid skeleton without using costly and toxic metal catalysts. Additionally, the resulting halides could be further exploited in subsequent palladium-catalyzed coupling reactions, so these compounds could act as potential intermediates for the construction of some valuable drug molecules.
- Qiu, Yi-Feng,Ye, Yu-Ying,Song, Xian-Rong,Zhu, Xin-Yu,Yang, Fang,Song, Bo,Wang, Jia,Hua, Hui-Liang,He, Yu-Tao,Han, Ya-Ping,Liu, Xue-Yuan,Liang, Yong-Min
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supporting information
p. 3480 - 3487
(2015/03/04)
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- Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: A highly enantioselective pathway for accessing chiral flavanones
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Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addi-tion of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod, the 1,4-addition of a variety of aryl-boronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions.
- He, Qijie,Wang, Jun,So, Chau Ming,Hayashi, Tamio,Bian, Zhaoxiang
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supporting information
p. 540 - 543
(2015/05/05)
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- CuO nanoparticles as an efficient catalyst for the synthesis of flavanones
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CuO nanoparticle was found to be an efficient catalyst for the synthesis of flavanones derivatives from the reactions between 2-hydroxyacetophenones and aromatic aldehydes at room temperature. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst. The structures of the synthesized substituted flavanones were confirmed by their Melting point, FT-IR,1 HNMR,13 CNMR and mass spectral analysis.
- Ahmady, Amanollah Zarei,Keshavarz, Mosadegh,Kardani, Maryam,Mohtasham, Neda
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p. 1841 - 1846
(2016/01/25)
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- Facile one-pot synthesis of flavanones using tetramethylguanidinum-based ionic liquids as catalysts
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Several tetramethylguanidinum-based ionic liquids (TMGILs) were prepared, characterized and used as catalysts in one-pot synthesis of flavanones. The results indicated that TMGILs composed of phenolate anion was beneficial for one-pot synthesis of flavanones, and [TMG][4-MeO-PhO] induced the good yields of flavanones owing to the electron-donating effect of methoxy substituent on phenolate anion. Furthermore, [TMG][4-MeO-PhO] was found to be used repetitively at least five times without obvious decrease in activity and quantity.
- Zhou, Yan,Huang, Wei,Chen, Xiang-Shu,Song, Zhi-Bin,Tao, Duan-Jian
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p. 1830 - 1836
(2019/11/28)
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- Nanosilica-supported dual acidic ionic liquid as a heterogeneous and reusable catalyst for the synthesis of flavanones under solvent-free conditions
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[Figure not available: see fulltext.] A nanosilica-supported dual acidic ionic liquid on the basis of 1-methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate was synthesized and used as an efficient, green, non-corrosive, non-toxic, heterogeneous, and reusable catalyst for the synthesis of some new and known substituted flavanones. The synthesis was done by the condensation of 2'-hydroxyacetophenone with different aldehydes and the subsequent cyclization of the resulting 2'-hydroxychalcone in the presence of the catalyst. High yields of the products, short reaction times, and solvent-free conditions characterize this new method.
- Rostamizadeh, Shahnaz,Zekri, Negar,Tahershamsi, Leili
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p. 526 - 530
(2016/02/16)
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- Impact of mono- and disubstitution on the colorimetric dynamic covalent switching chalcone/flavanone scaffold
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The effect of aryl substitution on various aspects of the interconversion of ortho-hydroxychalcones and flavanones has been studied using multiple spectroscopic techniques. Derivatization of the core scaffold predictably alters the midpoint pH of this equilibration process suggesting its viability for application as a functional colorimetric molecular switch.
- Muller, Brian M.,Mai, Jesse,Yocum, Reid A.,Adler, Marc J.
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supporting information
p. 5108 - 5114
(2014/07/08)
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- SAR studies of o-hydroxychalcones and their cyclized analogs and study them as novel inhibitors of cathepsin B and cathepsin H
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Cathepsins have emerged as a potential target for anti-cancer drug development. In the present study, we have synthesized three structurally related series of flavanoids i.e., 2′-hydroxychalcones, flavanones and flavones and assayed in vitro to study their inhibitory potency against cathepsin B and H, promising drug candidate for cancer therapy. Enzyme kinetics studies were carried out in presence of these compounds after preliminary proteolytic studies on endogenous protein substrates. SAR studies suggested that open chain flavanoids were better inhibitors as compared to their cyclized analogs. The most potent inhibitors among the three series were nitro substituted compounds 1g, 2g and 3g with Ki values of ~6.18 × 10-8 M, 4.8 × 10-7 M and 7.85 × 10-7 M for cathepsin B and Ki values of ~2.8 × 10-7 M, 31.8 × 10-6 M and 33.7 × 10 -6 M for cathepsin H, respectively. The relationship between chalcone, flavanones and flavone structures interpreted by docking studies on cathepsin B and H also provided useful insights.
- Raghav,Garg
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- Fe(HSO4)3/SiO2: An efficient and heterogeneous catalyst for one-pot synthesis of 2-aryl-chromene-4-ones (flavanones)
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Silica ferric hydrogensulphate is an efficient heterogeneous catalyst for cyclisation of 2-hydroxychalcones to their corresponding flavanones (chromanone). This intramolecular oxa-Michael reaction was carried out in high yields in the presence of electron donating and electron withdrawing groups in the chalcone structure. Also, we found that aniline can act as an organic co-catalyst in direct synthesis of flavanones from 2-hydroxyacethophenone and aldehydes in the presence of Fe(HSO4)3/SiO2. Flavanones were prepared in high yields in a new catalytic system with similar substituted effect in the indirect cyclisation method. The catalyst in all the above reactions is reusable without significant decreases in its activity after four times of recycling.
- Eshghi, Hossein,Rahimizadeh, Mohammad,Mousavi, Seyed Mohsen
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supporting information
p. 438 - 443
(2014/04/17)
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- Applications of caged-designed proton sponges in base-catalyzed transformations Dedicated to Professor Milan Kratochvíl for his 90th birthday anniversary.
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Superbasic properties of caged proton sponges (PSs) - substituted diazatetracyclo[4.4.0.13,10.15,8]dodecanes (DTDs) - were utilized in Knoevenagel and Claisen-Schmidt condensations, the Pudovik reaction, and Michael addition. This investigation covers the influence of the solvent, reaction temperature, catalyst loadings as well as the electronic properties of substituents upon the reaction. Moreover, we provided an activity comparison between our new base and a well-known and commercially available proton sponge (DMAN). The basicity (in MeCN) of our chosen DTD (pKBH+=21.7±0.1) exceeded the prototypal PS - 1,8-bis(dimethylamino)naphthalene (DMAN, pKBH+=18.6), by three orders of magnitude. We proved that DTDs are reasonably active species in monitored reactions, which is a consequence of a hydrogen bridge angle (~130°) between the two nitrogen atoms and the captured proton. We present here syntheses of aminoindolizine, substituted 4H-chromene, and flavanones, and the unexpected formation of a bis-addition product formed after Michael addition, all under mild conditions.
- Galeta, Juraj,Potá?ek, Milan
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- Asymmetric preparation of new N, N -dialkyl-2-amino-1,1,2-triphenylethanol catalysts and a kinetic resolution in the addition of diethylzinc to flavene-3-carbaldehydes
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Enantiopure N,N-dialkyl-(S)-2-amino-1,1,2-triphenylethanols were prepared using a new synthetic methodology and tested for their ability to catalyze the enantioselective addition of diethylzinc to aldehydes. The structural modification of N-substituents of the catalysts led us to identify N-methyl-N-(S)-1-phenyl-ethyl-substituted 4d as an effective catalyst for the addition. Also disclosed is a kinetic resolution of racemic flavene-3- carbaldehydes with the chiral catalyst.
- Kang, Seockyong,Baek, Jinho,Ko, Yikyung,Im, Chan,Park, Yongsun
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p. 630 - 634
(2013/04/23)
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- An efficient and facile synthesis of flavanones catalyzed by N-methylimidazole
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The use of N-methylimidazole as an efficient catalyst for the cyclization of 2'-hydroxychalcones to the corresponding flavanones in DMSO was investigated. The scope of this process was studied and various flavanones were obtained exclusively in good yields. Copyright
- Wang, Peng,Yang, Jiabin,Cai, Jin,Sun, Chunlong,Li, Lushen,Ji, Min
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p. 917 - 920
(2013/08/23)
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- Silica supported-double metal cyanides (DMCs): A green and highly efficient catalytic protocol for isomerisation of 2′-hydroxychalcones to flavanones
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Four different double metal cyanides (NiHCFe, CrHCFe, MnHCFe and ZnHCFe) were synthesized, followed by adsorbed on silica gel and used as Lewis acid catalyst in the isomerisation of substituted 2′-hydroxychalcones to flavanones under solvent-free (dry) condition. Optimization of the reaction condition, temperature effects, DMC catalysts loading and re-useable catalytic activity were further studied during the reaction. Among these catalysts, NiHCFe at 35 mol% loading gave excellent yield (90%) at 100 C temperature in 1.15 h. Catalyst (NiHCFe) easily recovered and re-used six times without much loss of its catalytic activity which gave 80-85% product yields each time. However, these DMCs were failed to give product in the solution phase even prolonging the reaction time at reflux temperature. Similarly, isomerization of substituted 2′-aminochalcones gave 2-5% yields either in solution phase or under solvent-free condition.
- Ahmed, Naseem,Konduru, Naveen Kumar,Praveen,Kumar, Anand,Kamaluddin
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p. 135 - 141
(2013/06/26)
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- Highly efficient and green synthesis of flavanones and tetrahydroquinolones
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Highly efficient and green catalytic conversion of 2′-hydroxy and 2′-amino chalcones to flavanones and tetrahydroquinolones is reported herein. 2′-Hydroxy and 2′-amino chalcones can be almost completely converted to flavanones and tetrahydroquinolones in just 2 min in the presence of piperidine and KOH under room temperature. Liquiritigenin is also efficiently synthesized under similar conditions.
- Zheng, Xuxu,Jiang, Heyan,Xie, Jingjing,Yin, Zhongyi,Zhang, Haidong
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p. 1023 - 1029
(2013/03/13)
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- Sodium perborate tetrahydrate-mediated transformations of 2′-hydroxychalcones to flavanones, flavones, and 3′, 5′-diiodoflavone under mild, environmentally friendly conditions
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Sodium perborate tetrahydrate has been utilized as a nucleophilic catalyst for facile conversion of 2′-hydroxychalcones to flavanones in warm aqueous acetonitrile, and then these chalcones, upon oxidative cyclization in warm acetic acid with an excess of the same reagent, afforded flavones in acceptable yields. One-pot synthesis of 3′,5′-diiodoflavone has been accomplished by diacetoxyiodobenzene-catalyzed iodination of 2′-hydroxychalcone with tetra-n-butylammonium iodide in acetic acid in the presence of sodium perborate as a terminal oxidant.
- Ganguly, Nemai C.,Chandra, Sumanta,Barik, Sujoy Kumar
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p. 1351 - 1361
(2013/05/09)
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- Hydromagnesite as an efficient recyclable heterogeneous solid base catalyst for the synthesis of flavanones, flavonols and 1,4-dihydropyridines in water
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A form of hydromagnesite (HM) with flower-like thin-sheet morphology was synthesized by an environmentally benign approach using simple conventional heating at moderate temperature without using any template in water as medium. The versatility of this HM catalyst was studied in the synthesis of flavanones, flavonols and the multicomponent synthesis of 1,4-dihydropyridines in water. The recyclability of catalyst was studied for six times and there was no appreciable loss in its catalytic activity. Copyright
- Rajesh, U. Chinna,Manohar, Sunny,Rawat, Diwan S.
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p. 3170 - 3178
(2013/12/04)
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- Synthetic approach to flavanones and flavones via ligand-free palladium(ii)-catalyzed conjugate addition of arylboronic acids to chromones
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The remarkable catalytic effects of Fe(OTf)3 in the context of the Pd(ii)-catalyzed conjugate addition of arylboronic acids to chromones were observed to yield a variety of flavanones under mild conditions. The addition of catalytic amounts of DDQ and KNO2 to the reactions exclusively yielded flavone analogs. The reaction scope for the transformation was fairly broad, affording good yields of a wide range of flavanones and flavones, which are privileged structures in many biologically active compounds.
- Kim, Donghee,Ham, Kyungrok,Hong, Sungwoo
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experimental part
p. 7305 - 7312
(2012/09/22)
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- Synthesis of flavanones, azaflavanones, and thioflavanones catalyzed by PMA-SiO2 as a mild, efficient, and reusable catalyst
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Cyclization of a variety of chalcones to flavanones catalyzed by 1 mol% phosphomolybdic acid (PMA) supported on silica as a mild, efficient, and reusable catalyst was carried out in high yields. PMA-SiO2 is an efficient, inexpensive, and green catalyst which gave high conversion yields and could be recycled up to three times without significant loss in activity. Springer-Verlag 2011.
- Sakirolla, Raghavendra,Yaeghoobi, Marzieh,Rahman, Noorsaadah Abd.
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experimental part
p. 797 - 800
(2012/09/07)
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- Iodine catalyzed one-pot synthesis of flavanone and tetrahydropyrimidine derivatives via Mannich type reaction
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A variety of functionalized flavanone derivatives and tetrahydropyrimidine derivatives were achieved under remarkably mild conditions. The combination of good to excellent yields, a simple work-up, and the high compatibility of functional groups makes this an attractive synthetic approach to access flavanone and tetrahydropyrimidine derivatives.
- Kavala, Veerababurao,Lin, Chunchi,Kuo, Chun-Wei,Fang, Hulin,Yao, Ching-Fa
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experimental part
p. 1321 - 1329
(2012/02/13)
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- Synthesis of 5-aryl-2-piperidino-5H-chromeno[3,4-c]pyridine-1-carbonitriles
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4-Chloro-2-aryl-2H-3-chromenecarbaldehydes 3a-g on reaction with malononitrile in ethanol in the presence of piperidine gave 5-aryl-2-piperidino- 5H-chromeno[3,4-c]pyridine-1-carbonitriles 4a-g in good yields. ARKAT-USA, Inc.
- Venkati,Reddy, S. Satyanarayana,Swamy,Ravikumar,Krupadanam, G. L. David
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scheme or table
p. 355 - 364
(2012/06/29)
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- Synthesis and biological evaluation of 2′-oxo-2,3-dihydro-3′H- spiro[chromene-4,5′-[1,3]oxazolidin]-3′yl]acetic acid derivatives as aldose reductase inhibitors
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Aldose reductase (ARL2) is the first enzyme in the polyol pathway which catalyzes the NADPH-dependent reduction of glucose to sorbitol. Its involvement on diabetic complications makes this enzyme a challenge therapeutic target widely investigated to limit
- Rapposelli, Simona,Da Settimo, Federico,Digiacomo, Maria,La Motta, Concettina,Lapucci, Annalina,Sartini, Stefania,Vanni, Michael
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experimental part
p. 372 - 385
(2012/01/11)
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- Synthesis and antifungal activities of natural and synthetic biflavonoids
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The synthesis of some natural and synthetic biflavonoids was performed in good overall yields starting from readily available materials via high yielding aldol and Ullmann condensations. Some of these compounds, especially bichalcones, display an interesting activity against fungi, higher than that of the corresponding monomers.
- Sagrera, Gabriel,Bertucci, Ana,Vazquez, Alvaro,Seoane, Gustavo
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p. 3060 - 3073
(2011/06/27)
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- Highly selective palladium-catalyzed direct c-h α-monoarylation of carbonyl compounds using water containing the surfactant polyoxyethylene- α-tocopheryl sebacate (PTS) as a solvent
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Highly selective direct C-H α-monoarylation reactions of 4-chromanones, ketones and 2-phenylacetaldehyde with aryl halides have been performed in satisfactory yields by using a tris(dibenzylideneacetone) dipalladium(0)/tri-tert-butylphosphine tetrafluoroborate catalyst system, potassium bicarbonate as the base and a solvent consisting of pure water containing a small amount of polyoxyethylene-α-tocopheryl sebacate (PTS). Analogous reaction conditions have been employed in a tandem process leading to phenyl-substituted isocoumarins from carbonyl compounds and methyl 2-bromobenzoate.
- Lessi, Marco,Masini, Tiziana,Nucara, Luca,Bellina, Fabio,Rossi, Renzo
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supporting information; experimental part
p. 501 - 507
(2011/04/15)
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- Synthesis of flavanones by use of anhydrous potassium carbonate as an inexpensive, safe, and efficient basic catalyst
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Anhydrous potassium carbonate has been utilized as an inexpensive, safe, and efficient basic catalyst for the synthesis of flavanones starting either from 2′-hydroxychalcones or from 2′-hydroxyacetophenones. In both the cases the favored reaction condition was either refluxing in a solvent with added catalyst or microwave irradiation on the catalyst.
- Mondal, Rina,Gupta, Arpita Das,Mallik, Asok K.
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p. 5020 - 5024
(2011/10/19)
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- Ytterbium(III) triflate: An efficient and simple catalyst for isomerization of 2′-hydroxychalcone and 2′-aminochalcones in ionic liquid
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Isomerization of 2′-hydroxychalcone and 2′-aminochalcone have been investigated using ytterbium(III) trifluromethanesulfonate {Yb(OTf) 3} (30 mol %) as Lewis acid catalyst in [bmim][BF4] ionic liquid. The effect of different metal triflates as Lewis acid, catalyst loading and reaction media was studied for this isomerization reaction. Advantages of the methodology include short reaction time, excellent yields, catalytic use of Lewis acid, and recovery and reuse of the catalyst. Copyright
- Rao, V. Kameswara,Rao, M. Sudershan,Kumar, Anil
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experimental part
p. 1356 - 1360
(2012/01/04)
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- An efficient catalytic synthesis of flavanones under green conditions
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An efficient and "green" catalytic conversion of 2′-hydroxychalcones to flavanones in 15 min in the presence of a simple amino acid and a base at room temperature is reported. Liquiritigenin was also efficiently synthesised under these conditions.
- Jiang, Heyan,Zheng, Xuxu,Yin, Zhongyi,Xie, Jingjing
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experimental part
p. 220 - 221
(2011/07/29)
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- Synthesis of chalcones and flavanones using Julia-Kocienski olefination
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A new application of Julia-Kocienski olefination for the synthesis of chalcones and flavanones has been described. 2-(Benzo[d]thiazol-2-ylsulfonyl)-1- phenylethanones have been developed as new reagents for direct Julia-Kocienski olefination with aldehydes in the presence of a base, afforded chalcones in good to excellent yields. Whereas, 2-(benzo[d]thiazol-2-ylsulfonyl)-1-(2- hydroxyphenyl)ethanone reacted with the aromatic aldehydes to furnish flavanones in good yields via one-pot intra-molecular cyclization.
- Kumar, Atul,Sharma, Siddharth,Tripathi, Vishwa Deepak,Srivastava, Suman
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scheme or table
p. 9445 - 9449
(2011/01/12)
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- PH-Dependent conjugate addition of arylboronic acids to α,β-unsaturated enones catalyzed by a reusable palladium(II)/cationic 2,2'-bipyridyl system in water under air
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A reusable Pd(NH3)2Cl2/cationic 2,2'-bipyridyl system for the catalysis of the conjugate addition of arylboronic acids to α,β-unsaturated enones in water under air was developed. Addition of arylboronic acids to both cyclic and acyclic enones progressed smoothly, providing the products in good to high yields, the best result being obtained when HBF4 was used to adjust the pH value to 1.0. After the reaction, the residual aqueous solution could be reused several times,making the reaction greener and reducing wastage of precious metals. Copyright
- Huang, Shao-Hsien,Wu, Tzu-Min,Tsai, Fu-Yu
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experimental part
p. 619 - 624
(2010/11/04)
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- Synthesis and cytotoxic activity of 4-aryl-4H-chromeno[4,3-d] [1,2,3] selenadiazoles
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Fourteen 4-Aryl-4H-chromeno[4,3-d][1,2,3] selenadiazole derivatives were synthesized by the reaction of fla-vonone-4-semicarbazones with SeO2. The structures of the target compounds 1a-n were elucidated by 1H NMR, IR spectra, ESI-MS and elemental analyses. The preliminary cytotoxic activities of 1a-n against K562, KB, A549, SMC-7721 and SGC-7901 cell lines were evaluated by MTT method, indicating that most compounds displayed moderate to good antiproliferative activities against K562 and KB cell lines. Compounds 1m and 1n, the most potent ones, were promising template for development of novel potent antitumor agents.
- Yin, Hong,Huang, Yueyan,Song, Guojie
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p. 721 - 725
(2013/01/09)
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