- AURONE DERIVATIVES AND USES THEREOF FOR CONTROLLING BACTERIA AND/OR FUNGI
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The present invention relates to aurones compounds of formula (I) and their uses for controlling a bacterium and/or a fungus. The invention also relates to the use of such compounds as phytoprotective and/or decontaminating and/or disinfectant agent and compositions comprising them.
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Page/Page column 35; 47
(2022/02/06)
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- In quest of small-molecules as potent non-competitive inhibitors against influenza
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A series of scaffolds namely aurones, 3-indolinones, 4-quinolones and cinnamic acid-piperazine hybrids, was designed, synthesized and investigated in vitro against influenza A/H1N1pdm09 virus. Designed molecules adopted different binding mode i.e., in 430-cavity of neuraminidase, unlike sialic acid and oseltamivir in molecular docking studies. All molecules reduced the viral titer and exhibited non-cytotoxicity along with cryo-protective property towards MDCK cells. Molecules (Z)-2-(3′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2f), (Z)-2-(4′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2g) and 2-(2′-Methoxy-phenyl)-1H-quinolin-4-one (3a) were the most interesting molecules identified in this research, endowed with robust potencies showing low-nanomolar EC50 values of 4.0 nM, 6.7 nM and 4.9 nM, respectively, compared to reference competitive and non-competitive inhibitors: oseltamivir (EC50 = 12.7 nM) and quercetin (EC50 = 0.56 μM), respectively. Besides, 2f, 2g and 3a exhibited good neuraminidase inhibitory activity in sub-micromolar range (IC50 = 0.52 μM, 3.5 μM, 1.3 μM respectively). Moreover, these molecules were determined as non-competitive inhibitors similar to reference non-competitive inhibitor quercetin unlike reference competitive inhibitor oseltamivir in kinetics studies.
- Malbari, Khushboo,Saha, Priyanka,Chawla-Sarkar, Mamta,Dutta, Shanta,Rai, Swita,Joshi, Mamata,Kanyalkar, Meena
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- METHOD FOR SYNTHESIZING (Z)-AURONE AND DERIVATIVE COMPOUNDS THEREOF
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One embodiment of the present invention is described below. Provided is (Z)-operon comprising o - (alkanone -1 - yl) phenol or its derivative compound in a thallium (Tl) catalyst and an cyclization step for cyclizing the compound under an organic solvent, and a method for producing the derivative compound.
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Paragraph 0147-0148; 0163-0167; 0198-0199
(2021/05/11)
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- Transition-metal-free synthesis of polysubstituted pyrrole derivatives via cyclization of methyl isocyanoacetate with aurone analogues
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Presented herein is an unprecedented transition-metal-free cyclization of methyl isocyanoacetate with aurone analogues catalyzed by NaOH. Various 2,3,4-trisubstituted pyrroles were obtained in excellent yields (up to 99%). The high efficiency of this synthetic procedure, coupled with the operational simplicity and atom economy, makes it an attractive method for the synthesis of polysubstituted pyrroles.
- Wang, Zhi-Peng,He, Yun,Shao, Pan-Lin
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supporting information
p. 5422 - 5426
(2018/08/12)
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- Catalytic Asymmetric [3 + 2] Cycloaddition Reaction between Aurones and Isocyanoacetates: Access to Spiropyrrolines via Silver Catalysis
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The first enantioselective formal [3 + 2] cycloaddition of aurone analogues with isocyanoacetates was developed via chiral Ag-complex catalysis. A variety of optically enriched spiro-1-pyrrolines were obtained in excellent yields, diastero- and enantioselectivities (up to 99% yield, >20:1 dr, >99% ee). This synthetic approach represents an extremely simple, efficient, and atom-economical method for spiro-1-pyrrolines synthesis.
- Wang, Zhi-Peng,Xiang, Sichuan,Shao, Pan-Lin,He, Yun
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p. 10995 - 11007
(2018/07/21)
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- One-pot Synthesis of Aurones through Oxidation-cyclization Tandem Reaction Catalyzed by Copper Nanoparticles Catalyst
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Aurones were synthesized through an oxidation-cyclization tandem reaction of 2-(1- hydroxyprop-2-ynyl)phenols catalyzed by copper nanoparticles (Cu NPs) with bipyridine as the ligand. In the reaction, oxygen worked as a green and mild oxidant to give the best results. Cu NPs were dually activated by bipyridine ligand and water, and showed highly efficient catalytic activities to the oxygen oxidation and the cylization to give aurones and flavonoids.
- Yu, Min,Liu, Guangxiang,Han, Chengyan,Zhu, Li,Yao, Xiaoquan
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- Unusual Olefinic C-H Functionalization of Simple Chalcones toward Aurones Enabled by the Rational Design of a Function-Integrated Heterogeneous Catalyst
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Flavonoids, which are ubiquitous plant secondary metabolites obtained from chalcones, mostly possess 6-membered C-rings derived from 6-endo-trig cyclization of chalcones. However, aurones, which are a class of flavonoids that rarely occur naturally, possess unusual 5-membered C-rings biosynthesized from chalcones by mainly performing B-ring oxidation. Therefore, the chemical catalytic transformation from simple chalcones into aurones is attractive, because it overcomes the drawback of known limited enzyme catalysis. The catalytic transformation, however, has not yet been reported because of the preferential 6-membered ring formation as with the biosynthesis and the need for rare intramolecular olefinic C-H functionalization. Here, we developed the catalytic olefinic C-H functionalization of simple chalcones toward various aurones enabled by the rational design of a function-integrated heterogeneous catalyst - a Pd-on-Au bimetallic nanoparticle catalyst supported on CeO2 - using O2 in air as the sole oxidant without any additives. In this system, the four conditions that were required for the challenging transformation toward aurones were achieved by the respective components of the catalyst: (a) a supported Pd catalyst: a catalyst for the olefinic C-H functionalization of chalcones toward aurones, (b) an Au promoter: an improvement in the catalytic activity by stabilizing Pd(0), (c) a CeO2 support: the inhibition of the 6-endo-trig cyclization utilizing the adsorption of chalcones, and (d) a Pd-on-Au structure: the inhibition of Au-catalyzed flavone synthesis. This catalytic transformation will promote not only the pharmaceutical study of aurones but also the rational design of a heterogeneous catalyst for the development of organic reactions that are not yet realized by homogeneous catalysts or biocatalyst.
- Yatabe, Takafumi,Jin, Xiongjie,Mizuno, Noritaka,Yamaguchi, Kazuya
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p. 4969 - 4978
(2018/06/08)
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- "On water" synthesis of aurones: First synthesis of 4,5,3',4',5'-pentamethoxy-6-hydroxyaurone from Smilax riparia
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A simple and green method for the synthesis of aurones by condensation of benzofuranone with aromatic aldehyde in neat water has been developed. The main advantages of this protocol include good yields, absence of catalyst, reagent, organic solvent, work-up and chromatographic purification. 4,5,3',4',5'-Pentamethoxy-6-hydroxyaurone, isolated from Smilax riparia was synthesized for the first time from 3-benzyloxy-4,5-dimethoxybenzaldehyde in five steps. {figure presented}.
- Venkateswarlu, Somepalli,Murty, Gandrotu Narasimha,Satyanarayana, Meka
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p. 303 - 314
(2017/06/19)
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- THERAPEUTIC AURONES
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Substituted aurones were found to have antitrypanosomal, antifungal and immunomodulatory activity. The invention provides novel aurone compounds, pharmaceutical compositions, and methods encompassing medical and veterinary applications.
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Page/Page column 84; 85
(2017/11/10)
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- Synthesis, structure–activity relationship and molecular docking of 3-oxoaurones and 3-thioaurones as acetylcholinesterase and butyrylcholinesterase inhibitors
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The present study describes efficient and facile syntheses of varyingly substituted 3-thioaurones from the corresponding 3-oxoaurones using Lawesson's reagent and phosphorous pentasulfide. In comparison, the latter methodology was proved more convenient, giving higher yields and required short and simple methodology. The structures of synthetic compounds were unambiguously elucidated by IR, MS and NMR spectroscopy. All synthetic compounds were screened for their inhibitory potential against in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Molecular docking studies were also performed in order to examine their binding interactions with AChE and BChE human proteins. Both studies revealed that some of these compounds were found to be good inhibitors against AChE and BChE.
- Mughal, Ehsan Ullah,Sadiq, Amina,Murtaza, Shahzad,Rafique, Hummera,Zafar, Muhammad Naveed,Riaz, Tauqeer,Khan, Bilal Ahmad,Hameed, Abdul,Khan, Khalid Mohammed
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p. 100 - 106
(2016/12/18)
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- Synthesis, molecular docking studies and biological evaluation of 3-iminoaurones as acetylcholinesterase and butyrylcholinesterase inhibitors
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Background: A new series of aurone-hydrazones have been designed and synthesized in order to explore new bioactive compounds, which could have potential to be used as active drugs against Alzheimer’s disease. Methods: The newly synthesized compounds were characterized by various spectroscopic techniques (IR, mass spectrometry and NMR spectroscopy) and evaluated in vitro for their inhibitory potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. All target compounds exhibited varied degree of IC50 values compared to standard Donepezil. Among the series, the compound 6c was found as a potent dual inhibitor of AChE and BChE having IC50 values 0.92±0.01 and 2.25±0.01 μM respectively. Results and Conclusion: The experimental results were further supported by molecular docking analysis. Both studies showed that some of these compounds are interesting inhibitors against AChE and BChE enzymes.
- Mughal, Ehsan Ullah,Sadiq, Amina,Khan, Bilal Ahmad,Zafar, Muhammad Naveed,Ahmed, Ishtiaq,Zubair, Muhammad
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p. 1035 - 1041
(2017/09/12)
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- Scaffold-Hopping of Aurones: 2-Arylideneimidazo[1,2-a]pyridinones as Topoisomerase IIα-Inhibiting Anticancer Agents
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Scaffold-hopping of bioactive natural product aurones has been studied for the first time. 2-Arylideneimidazo[1,2-a]pyridinones as potential topoisomerase IIα (hTopoIIα)-targeting anticancer compounds were considered. A multifunctional activator, polyphos
- Priyadarshani, Garima,Nayak, Anmada,Amrutkar, Suyog M.,Das, Sarita,Guchhait, Sankar K.,Kundu, Chanakya N.,Banerjee, Uttam C.
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p. 1056 - 1061
(2016/12/18)
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- An efficient synthesis of aurone derivatives by the tributylphosphine-catalyzed regioselective cyclization of o-alkynoylphenols
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An organocatalytic regioselective synthes is of aurones from o-alkynoylphenols was achieved. A catalytic amount of tributylphosphine select ively induced the 5-exo cyclization of o-alkynoylphenols under ambient conditions leading to aurone derivatives in high to excellent yields.
- Saito, Koya,Yoshida, Masahito,Doi, Takayuki
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supporting information
p. 141 - 143
(2015/02/19)
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- Regioselective synthesis of aurone derivatives via PBu3-catalyzed cyclization of 2-alkynoylphenols
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Aurone derivatives were synthesized in good to high yields by PBu3-catalyzed intramolecular 5-exo cyclization of 2-alkynoylphenols. The reaction proceeds in high regioselectivity without forming 6-endo cyclization products.
- Liu, Changqing,Zhang, Zhannan,Zhang, Jitan,Liu, Xing,Xie, Meihua
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supporting information
p. 1233 - 1237
(2015/02/02)
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- Aurones as histone deacetylase inhibitors: Identification of key features
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In this study, a total of 22 flavonoids were tested for their HDAC inhibitory activity using fluorimetric and BRET-based assays. Four aurones were found to be active in both assays and showed IC50 values below 20 μM in the enzymatic assay. Molecular modelling revealed that the presence of hydroxyl groups was responsible for good compound orientation within the isoenzyme catalytic site and zinc chelation.
- Zwick, Vincent,Chatzivasileiou, Alkiviadis-Orfefs,Deschamps, Nathalie,Roussaki, Marina,Simes-Pires, Claudia A.,Nurisso, Alessandra,Denis, Iza,Blanquart, Christophe,Martinet, Nadine,Carrupt, Pierre-Alain,Detsi, Anastasia,Cuendet, Muriel
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supporting information
p. 5497 - 5501
(2014/12/12)
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- Construction of the flavones and aurones through regioselective carbonylative annulation of 2-bromophenols and terminal alkynes
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The easily available and efficient catalyst containing a benzimidazolium ligand and PdCl2(PPh3)2 demonstrated excellent catalytic activity to construct the flavones and aurones, respectively. This reaction can be operated under mild conditions, affording the desired products in moderate to good yields. This protocol was used to prepare the flavones and aurones by a slight modification of amines.
- Liu, Jianming,Liu, Muwen,Yue, Yuanyuan,Zhang, Ningfei,Zhang, Yuanli,Zhuo, Kelei
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supporting information
p. 1802 - 1807
(2013/04/24)
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- Ethylenediamine diacetate (EDDA) mediated synthesis of aurones under ultrasound: Their evaluation as inhibitors of SIRT1
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An improved synthesis of functionalized aurones has been accomplished via the reaction of benzofuran-3(2H)-one with a range of benzaldehydes in the presence of a mild base EDDA under ultrasound. A number of aurones were synthesized (within 5-30 min) and the molecular structure of a representative compound determined by single crystal X-ray diffraction study confirmed Z-geometry of the C-C double bond present within the molecule. Some of the compounds synthesized have shown SIRT1 inhibiting as well as anti proliferative properties against two cancer cell lines in vitro. Compound 3a [(Z)-2-(5-bromo-2-hydroxybenzylidene) benzofuran-3(2H)-one] was identified as a potent inhibitor of SIRT1 (IC50 = 1 μM) which showed a dose dependent increase in the acetylation of p53 resulting in induction of apoptosis.
- Manjulatha, Khanapur,Srinivas,Mulakayala, Naveen,Rambabu,Prabhakar,Arunasree, Kalle M.,Alvala, Mallika,Basaveswara Rao,Pal, Manojit
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supporting information
p. 6160 - 6165
(2012/10/30)
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- Water-promoted, silver-phosphine complex-catalyzed stereoselective cyclization of 2-(1-Hydroxy-3-arylprop-2-ynyl)phenols leading to a highly efficient approach to aurones
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Silver-phosphine complexes can be utilized as highly efficient catalysts for the cyclization of 2-(1-hydroxy-3-arylprop-2-ynyl)phenols (1) to give product 2, key intermediates to synthesize aurones (4), with good yields and stereoselectivities in water-to
- Lin, Mingdeng,Yu, Min,Han, Chengyan,Li, Chao-Jun,Yao, Xiaoquan
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p. 3228 - 3236
(2011/09/30)
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- Natural and synthetic 2′-hydroxy-chalcones and aurones: Synthesis, characterization and evaluation of the antioxidant and soybean lipoxygenase inhibitory activity
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A series of 2′-hydroxy-chalcones and their oxidative cyclization products, aurones, have been synthesized and tested for their antioxidant and lipoxygenase inhibitory activity. The natural product aureusidin (31) was synthesized in high yield by a new approach. An extensive structure-relationship study was performed and revealed that several chalcones and aurones possess an appealing pharmacological profile combining high antioxidant and lipid peroxidation activity with potent soybean LOX inhibition.
- Detsi, Anastasia,Majdalani, Maya,Kontogiorgis, Christos A.,Hadjipavlou-Litina, Dimitra,Kefalas, Panagiotis
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experimental part
p. 8073 - 8085
(2010/03/24)
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- Synthesis, structural revision, and biological activities of 4′-chloroaurone, a metabolite of marine brown alga Spatoglossum variabile
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4′-Chloroaurone (1a), the only aurone reported from a marine source, Spatoglossum variabile was synthesized from 2-hydroxyacetophenone along with six structural analogs. The products obtained were Z-isomers and these were converted into E-isomers by photo
- Venkateswarlu, Somepalli,Panchagnula, Gopala K.,Gottumukkala, Aditya L.,Subbaraju, Gottumukkala V.
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p. 6909 - 6914
(2008/02/11)
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- Synthesis and insect antifeedant activity of aurones against spodoptera litura larvae
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A series of aurones were prepared from various phenols via phenoxy acetic acids and coumaranones and evaluated for insect antifeedant activity against the common cutworm (Spodoptera litura). The naturally occurring aurone was most active at an ED50 of 0.12 μmol/cm2. The synthetic precursor, coumaranones, showed that the introduction of methoxyl and methyl groups to the benzene ring increased insect antifeedant activity. Similarly, the tested aurones showed that the introduction of methoxyl group to the A and/or B rings increased the insect antifeedant activity, but 4,5,6- and 3 ,4 ,5 -trisubstituted compounds did not show this activity in this test. The hydroxylation of aurones in the B ring should be disadvantageous for insect antifeedant activity against S. litura. Although the melting points did not correlate well with the insect antifeedant activity, compounds that were nearly inactive had high melting points. A significant correlation was noted between biological activity (pED50) and a hydrogen-bonding parameter calculated from the Rf value obtained from SiOH thin-layer chromatography and a lipophilicity parameter (log k) calculated from the retention time in ODS high-performance liquid chromatography. The respective correlation coefficients (r) were -0.83 and -0.70. The introduction of alkoxy and alkyl groups along with adequate hydrogen bonding seems to contribute to the antifeedant activity of the compounds tested.
- Morimoto, Masanori,Fukumoto, Hiromi,Nozoe, Toki,Hagiwara, Ai,Komai, Koichiro
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experimental part
p. 700 - 705
(2009/10/01)
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- An environmentally benign synthesis of aurones and flavones from 2′-acetoxychalcones using n-tetrabutylammonium tribromide
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A wide variety of aurones (3a-f) can be prepared exclusively from 2′-acetoxychalcones (1a-f) in high yields in two steps, by bromination using n-tetrabutylammonium tribromide (TBATB) in the presence of CaCO3 in CH2Cl2-MeOH (5:2) at 0-5°C followed by cyclization of the brominated products 2a-f on treating with 0.2 M ethanolic KOH solution at 0-5°C, respectively. In contrast various flavone derivatives 6a-f can be obtained exclusively from compounds 1a-f in fairly good yields, by brominating with the same reagent in CH2Cl2, followed by dehydrobromination and finally cyclization on treating with 0.1 M NaOMe solution.
- Bose, Gopal,Mondal, Ejabul,Khan, Abu T,Bordoloi, Manob J.
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p. 8907 - 8909
(2007/10/03)
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- REACTION OF CHALOCONES WITH N-BROMOSUCCINIMIDE. SYNTHESIS OF AURONES
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The reaction of 2'-OR-4-R1 chalcone with N-bromosuccinimide is reported.It was found that the structure of the product depends on the nature of the substituents R and R1.The prepared α-bromo-β-methoxydihydrochalcones were converted to the corresponding aurones.
- Litkei, D.,Khilya, V. P.,Tokesh, A. L.,Antush, Sh.,Turov, A. V.
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p. 432 - 440
(2007/10/03)
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- Dimethyldioxirane epoxidation of aurones and isoflavones
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The synthesis of the corresponding epoxides 2 and 4 by epoxidation of aurones (2-benzylidenebenzofuran-3(2H)-ones, 1) and isoflavones (3-aryl-4H-1-benzopyran-4-ones, 3) with dimethyldioxirane at subambient temperatures is reported. These acid- and base-se
- Adam,Hadjiarapoglou,Levai
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p. 436 - 438
(2007/10/02)
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- REACTION DE DIVERSES 2-ARYLIDENE-BENZOFURAN-3-ONES AVEC LA DIPHENYLNITRILIMINE. UNE NOUVELLE SYNTHESE D'ORTHO-HYDROXYBENZOYLPYRAZOLES
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A new synthesis of ortho-hydroxybenzoylpyrazoles in one step from 2-arylidene-benzofuran-3-ones, via cycloaddition route and a adduct rearrangement, is recorded.
- M'Sadek, Moncef,Rammah, Mohammed,Schmitt, Gerard,Vebrel, Joel
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p. 323 - 328
(2007/10/02)
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- ALUMINA-MEDIATED CONDENSATION. A SIMPLE SYNTHESIS OF AURONES
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A simple and high yielding synthesis of aurones (2-phenylmethylene-3(2H)-benzofuranones) is described which occurs under mild conditions on alumina surface using readily available benzofuranones and arylaldehydes.Key Words: Aurones; 2-Phenylmethylene-3(2H)-benzofuranones; Solid Surface; Alumina
- Varma, Rajender S.,Varma, Manju
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p. 5937 - 5940
(2007/10/02)
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- Preparative and Regiochemical Aspects of the Palladium-Catalyzed Carbonylative Coupling of 2-Hydroxyaryl Iodides with Ethynylarenes
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The title reaction has been conveniently carried out in DMF at 60 deg C under 1 atm CO pressure using DBU as the base and Pd(OAc)2(DPPF)2 as the catalyst to afford generally mixtures of flavones 4 and aurones 5 in varying yields, depending on the substituents in the both reactants.Factors controlling the regioselectivity for 4 or 5 formation in this and in similar, previously reported, coupling procedures have been examined.
- Ciattini, Pier Giuseppe,Morera, Enrico,Ortar, Giorgio,Rossi, Sabina Strano
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p. 6449 - 6456
(2007/10/02)
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- Intramolecular Cyclisation Catalysed by Silver(I) Ion; a Convenient Synthesis of Aurones
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Silver(I) ion catalysed intramolecular cyclisation of (1a-d) at room temperature gives corresponding aurone (2a-d) as the major product with a trace amount of the flavone; compounds (1a-d) could be prepared by the addition of the corresponding lithium acetylide (4a-b) to the substituted salicyl aldehyde (5a-c), followed by MnO2 oxidation.
- Jong, Ting-Ting,Leu, Shang-Jen
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p. 423 - 424
(2007/10/02)
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- Amine-effected cyclization of chalcone dihalides to aurones
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The possibility of employing the amine-catalysed cyclization of αβ-dibromodihydrochalcones and α-bromochalcones as a general synthesis of aurones was studied using cyclohexylamine and the most representative member of each class of these αβ-disubstituted ketones and α-halogeno chalcones. Overall yields of heterocyclic products were generally poor except from 4′6′-dimethoxy- and 3-nitro-substituted chalcone systems; aurones were obtained in fair yield from the former and in excellent yield from the latter. 22′-Diacetoxychalcone dibromide and 22′-diacetoxy-α-bromochalcone cyclised to a 2-benzoylbenzofuran to the exclusion of the corresponding aurone and flavone.
- Donnelly, John A.,Emerson, Geraldine M.
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p. 7227 - 7236
(2007/10/02)
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- Regioselective synthesis of 2-arylidene coumaran-3-ones by dye-sensitized photooxygenation of 2-hydroxyphenyl-styrylketones in the presence of sodium dodecyl sulphate
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2′-Hydroxyphenylstyrylketones when subjected to dye- sensitized photooxygenation in the presence of sodium dodecylsulphate (8x × 10-3M) in methanol, yielded the corresponding oxidatively cyclized products, i.e., 2-aryl idenecoumaran 3-ones and
- Chawla, H. Mohindra,Sharma, S. Kumar
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p. 1611 - 1624
(2007/10/02)
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- Cyclodehydrogenation of 2'-hydroxychalcones and dehydrogenation of flavanones using nickel peroxide
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Nickel peroxide oxidation of 2'-hydroxychalcones (1) gives flavones (3) in moderate yields, aurones (4) are also formed in cases where the 2/4 position of the starting 1 bears either a strong ?-donor or a ?-acceptor substituent.Flavanones (2) are dehydrogenated with this reagent to the corresponding flavones (3) in very good yields.
- Mallik, Uttam K.,Murari, M. Saha,Mallik, Asok K.
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p. 970 - 972
(2007/10/02)
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- Cyclodehydrogenation of 2'-Hydroxychalcones with DDQ: A Simple Route for Flavones and Aurones
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The oxidation of 2'-hydroxychalcones with 2,3-dichloro-5,6-dicyano-p-benzoquinone provides a useful synthetic route for flavones and aurones.
- Imafuku, Kimiaki,Honda, Masaaki,McOmie, J. F. W.
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p. 199 - 201
(2007/10/02)
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- FLAVONOIDS, 39. THE REACTION OF 3-MESYLOXYFLAVANONES WITH O- AND S-NUCLEOPHILES, SYNTHESIS OF 3-THIOCYANATO- AND 3-ACETYLTHIO-FLAVANONES
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The action of either cyanate or acetate ions on trans-3-mesyloxyflavanones 1 led to the formation of flavones 2 and aurones while the reaction with the respective S-nucleophiles (thiocyanate and thioacetate ions) resulted in cis- and trans-3-thiocyanato- and 3-acetylthioflavanones (6 and 11).The participation of the concurrent nucleophilic substitution, β-elimination and elimination with ring-contraction is dependent on the "hard-soft" character of the nucleophile and the increase of the "soft" character favours the displacement.
- Patonay, Tamas,Litkei, Gyoergy,Bognar, Rezsoe
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p. 3425 - 3430
(2007/10/02)
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- FLAVONOIDS, XXXVII. RING CONTRACTION AND RING ENLARGEMENT REACTIONS WITH TRIMETHYLSILYL AZIDE IN THE FIELD OF FLAVONOIDS
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The reaction of flavanone with trimethylsilyl azide (TMSA) in trifluoroacetic acid (TFA) afforded by ring expansion, 2,3-dihydro-2-phenyl-1,4-benzoxazepin-5(4H)-one or 2,3-dihydro-2-phenyl-4H-tetrazolo-1,4-benzoxazepine.The same products could be isolated using sodium azide in TFA.An unknown intermediate of the Schmidt reaction was also isolated.Treatment of 2'-hydroxychalcone with TMSA or sodium azide in TFA resulted in isoflavone and trans-3-aminoflavanone.The reaction of 4-substituted 2'-hydroxychalcones with TMSA in dimethylformamide gave, with ring contraction, aurones and flavones.
- Litkei, Gy.,Patonay, T.
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- FLAVONOIDS, XXXVI REACTION OF 3-ALKYL- OR -ARYLSULFONYLOXYFLAVANONES WITH AMINES. SYNTHESIS OF 3-DIALKYLAMINOFLAVANONES
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Reactions of 3-alkyl- or -arylsulfonyloxyflavanones (1a-h) with primary and tertiary amines gave mixtures of the corresponding flavones (2a-d) and aurones (3a-d), while with secondary amines, in addition to 2 and 3, 3-dialkylaminoflavanones (6-9) were also obtained.The factors which determine the ratio of products are discussed.Treatment of the 3-dialkylaminoflavones 6a and 7 with DDQ gave 3-dialkylaminoflavanones (10, 11); treatment with alkali in methanol afforded 2-dialkylamino-2-benzylcoumaran-3-ones (12, 13).
- Patonay, T.,Litkei, Gy.,Bognar, R.
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p. 135 - 146
(2007/10/02)
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- Synthesis and Reaction of 3-Bromoflavanones with DMSO
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Bromination of flavanones (I) with (2-carboxyethyl)triphenylphosphonium perbromide gives the corresponding 3-bromoflavanones (II) which when treated with DMSO at room temperature undergo dehydrobromination to flavones (III).
- Sharma, T. C.,Pawar, S. R.,Reddy, N. J.,Donnelly, John A.
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