- Ligand-promoted, copper nanoparticles catalyzed oxidation of propargylic alcohols with TBHP or Air as Oxidant
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A highly efficient oxidation of propargylic alcohols to ynones was catalyzed by copper nanoparticles (Cu Nps) with TBHP as an oxidant at room temperature. With bipyridine as the ligand, the reaction was accelerated significantly and led in good to excellent yields to a variety of propargylic alcohols. Furthermore, with Cu Nps as the catalyst, molecular oxygen in air could be utilized as oxidant effectively in the presence of bpy ligand. Georg Thieme Verlag Stuttgart - New York.
- Han, Chengyan,Yu, Min,Sun, Weijiang,Yao, Xiaoquan
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- Palladium-catalyzed synthesis of aurone from salicyloyl chloride and phenylacetylene
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Salicyloyl chloride has been found to react with phenylacetylene under the catalytic action of a palladium(O) complex with trioctylamine as ligand to give o-hydroxyphenyl phenylalkynyl ketone as the main product.The ketone undergoes selective cyclization to aurone in the presence of a palladium(O)-triphenylphosphine catalyst.
- An, Zhong-wei,Catellani, Marta,Chiusoli, Gian Paolo
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Read Online
- Bioactivity-Guided Synthesis Accelerates the Discovery of 3-(Iso)quinolinyl-4-chromenones as Potent Fungicide Candidates
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Fungal infections could cause tremendous decreases in crop yield and quality. Natural products, including flavonoids and (iso)quinolines, have always been an important source for lead discovery in medicinal and agricultural chemistry. To promote the discovery and development of new fungicides, a series of 3-(iso)quinolinyl-4-chromenone derivatives was designed and synthesized by the active substructure splicing principle and evaluated for their antifungal activities. The lead optimization was guided by bioactivity. The bioassay data revealed that the 3-quinolinyl-4-chromenone 13 showed significant in vitro activities against S. sclerotiorum, V. mali, and B. cinerea with EC50 values of 3.65, 2.61, and 2.32 mg/L, respectively. The 3-isoquinolinyl-4-chromenone 25 exhibited excellent in vitro activity against S. sclerotiorum with an EC50 value of 1.94 mg/L, close to that of commercial fungicide chlorothalonil (EC50 = 1.57 mg/L) but lower than that of boscalid (EC50 = 0.67 mg/L). For V. mali and B. cinerea, 3-isoquinolinyl-4-chromenone 25 (EC50 = 1.56, 1.54 mg/L) showed significantly higher activities than chlorothalonil (EC50 = 11.24, 2.92 mg/L). In addition, in vivo experiments proved that compounds 13 and 25 have excellent protective fungicidal activities with inhibitory rates of 88.24 and 94.12%, respectively, against B. cinerea at 50 mg/L, while the positive controls chlorothalonil and boscalid showed inhibitory rates of 76.47 and 97.06%, respectively. Physiological and biochemical studies showed that the primary action of mechanism of compounds 13 and 25 on S. sclerotiorum and B. cinerea may involve changing mycelial morphology and increasing cell membrane permeability. In addition, compound 13 may also affect the respiratory metabolism of B. cinerea. This study revealed that compounds 13 and 25 could be promising candidates for the development of novel fungicides in crop protection.
- Wang, Wei,Zhang, Shan,Wang, Jianhua,Wu, Furan,Wang, Tao,Xu, Gong
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p. 491 - 500
(2021/02/03)
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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 0131-0133
(2021/05/11)
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- Copper-catalyzed method for preparing aldehyde or ketone compound by oxidizing alcohol with oxygen as oxidizing agent and application
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The invention discloses a copper-catalyzed method for preparing an aldehyde or ketone compound by oxidizing alcohol with oxygen as an oxidizing agent. Reaction is performed in an organic solvent for 4-48 hours at room temperature by using copper salt and nitroxide free radicals as catalysts and oxygen or air as an oxidizing agent to efficiently oxidize an alcohol compound into the corresponding aldehyde or ketone compound. The method is simple to operate, free of chlorides corrosive to equipment, available in raw materials and reagents, mild in reaction conditions, wide in substrate universality, good in functional group compatibility, convenient in separation and purification, environmentally friendly in the whole process and free of pollution, and is a method suitable for industrial production.
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Paragraph 0028-0030; 0091-0093
(2020/08/18)
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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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- One Pot Synthesis of γ-Benzopyranones via Iron-Catalyzed Aerobic Oxidation and Subsequent 4-Dimethylaminopyridine Catalyzed 6-endo Cyclization
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One-pot synthesis of γ-benzopyranones was realized in decent yields and excellent regioselectivities via iron-catalyzed aerobic oxidation and 4-dimethylaminopyridine-catalyzed cyclization of related propargylic alcohols. Derivatizations to aromatic substituted γ-benzopyranones and synthesis of naturally occurring 3′,4′-dimethoxyflavone have also been realized. (Figure presented.).
- Zhai, Di,Chen, Lingzhu,Jia, Minqiang,Ma, Shengming
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supporting information
p. 153 - 160
(2017/11/23)
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- Divergence in Ynone Reactivity: Atypical Cyclization by 3,4-Difunctionalization versus Rare Bis(cyclization)
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Functionalized ynones can be activated by Tf2C=CH2, which was generated in situ, to form zwitterionic species. These species were trapped in an intramolecular fashion by several nucleophiles to generate two major types of triflones in a divergent manner. Through fine-tuning of the reaction temperature, bis(triflyl)-6-membered- or (triflyl)-5-membered-fused-heterocycles were achieved in reasonable yields in a totally selective manner. In this way, bis(triflyl)flavones, bis(triflyl)thioflavones, bis(triflyl)selenoflavones, (triflyl)benzothienopyrans, (triflyl)benzoselenophenopyrans, (triflyl)vinyl aurones, and (triflyl)pyranoindoles were constructed. Conceivable mechanistic pathways were suggested on the basis of the isolation of several intermediates and the results from control experiments.
- Alcaide, Benito,Almendros, Pedro,Lázaro-Milla, Carlos,Delgado-Martínez, Patricia
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supporting information
p. 8186 - 8194
(2018/06/15)
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- Dual-immobilized copper catalyst: Carbon nitride-supported copper nanoparticles catalyzed oxidation of propargylic alcohols
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Copper nanoparticles were supported and modified by carbon nitride, which was utilized as support and might work as a kind of immobilized N-donor ligand. The modified nanoparticle catalyst was evaluated with the oxidation of propargylic alcohols and showed highly catalytic efficiency as well as significant ligand or support effect in the reaction. The dual-immobilized nanoparticle catalyst could be recycled for 3 times at least without an obvious decrease in catalytic activities.
- Lv, Wei,Tian, Jing,Deng, Nan,Wang, Yan,Zhu, Xiaoshu,Yao, Xiaoquan
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supporting information
p. 1312 - 1316
(2015/03/04)
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- Synthesis of 1,3-thioxoketones from salicylaldehyde
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A method for the synthesis of monothiodibenzoylmethanes was developed. The method involves a reaction of potassium thioacetate with 1-(2-hydroxyphenyl)-3- phenylpropynone prepared from salicylaldehyde.
- Semenova,Yarovenko,Levchenko,Krayushkin
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p. 1022 - 1025
(2014/03/21)
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- Synthesis of chromones through LiOtBu/air-mediated oxidation and regioselective cyclization of o-hydroxyphenyl propargyl carbinols
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A cascade oxidative cyclization reaction for the synthesis of chromone derivatives was developed by using LiOtBu as a mediator and air as an oxidant. The reaction was carried out without the assistance of a transition metal under mild conditions to afford the chromones in good yields with high regioselectivities. A tandem reaction for the synthesis of various chromones was developed. LiOtBu was used as a mediator and air was used as a clean oxidant. The reaction generally showed high regioselectivity under mild conditions. Extensive research showed that dehydrogenative oxidation of the alcohols under strongly basic conditions was the crucial step, and Li+ was also found to play an important role in this process. Copyright
- Zhang, Shuai,Wan, Changfeng,Wang, Qiang,Zhang, Baiqun,Gao, Lingfeng,Zha, Zhenggen,Wang, Zhiyong
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supporting information
p. 2080 - 2083
(2013/05/09)
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- Synthesis of γ-benzopyranone by TfOH-promoted regioselective cyclization of o-alkynoylphenols
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Regioselective cyclization of o-alkynoylphenols forming γ-benzopyranones has been demonstrated. Trifluoromethanesulfonic acid (TfOH) induced 6-endo cyclization of o-alkynoylphenols without forming 5-exo cyclized benzofuranone derivatives to provide the corresponding γ-benzopyranones in high yields.
- Yoshida, Masahito,Fujino, Yuta,Doi, Takayuki
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supporting information; experimental part
p. 4526 - 4529
(2011/10/09)
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- Regioselective synthesis of flavone derivatives via DMAP-catalyzed cyclization of o-alkynoylphenols
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A catalytic amount of DMAP promoted cyclization of o-alkynoylphenols via a 6-endo cyclization mode leading to flavone derivatives in high yields without forming 5-exo cyclized aurone derivatives. Utilizing this method, methoxy substituted flavone and alkyl substituted γ-benzopyranone derivatives were synthesized.
- Yoshida, Masahito,Fujino, Yuta,Saito, Koya,Doi, Takayuki
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experimental part
p. 9993 - 9997
(2012/02/06)
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- Versatile and expeditious synthesis of aurones via AuI-catalyzed cyclization
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(Chemical Equation Presented) Aurones are conveniently formed in a three-step procedure including a goldI-catalyzed cyclization of 2-(1-hydroxyprop-2-ynyl)phenols as a highly regio- and stereoselective key step. A wide diversity of derivatives can be obtained starting from substituted salicylaldehydes. Synthesis of natural 4,6,3′,4′-tetramethoxyaurone and structure revision of two natural products (dalmaisione D and 4′-chloroaurone) were achieved.
- Harkat, Hassina,Blanc, Aurelien,Weibel, Jean-Marc,Pale, Patrick
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p. 1620 - 1623
(2008/09/16)
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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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- Ring Closure to Ynone Systems: 5- and 6-endo- and -exo-dig Modes
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The rates of cyclisation of 2-hydroxy-2-methyl-5-arylpent-4-yn-3-ones in trifluoroacetic acid are reported.An approximate ρ value of -4.0 (using ?+) and a kinetic isotope effect KTFA/KTFA-d' of 4.2 are observed, which suggest that the reaction proceeds via rate-limiting triple-bond protonation and does not entail carbonyl protonation along the reaction co-ordinate.The base-catalysed ring closure occurs via the vinilyc carbanion.A similar mechanistic picture appears to be involved in the cyclisation of 1-(2-hydroxyphenyl)-3-arylprop-2-yn-1-ones which yield a mixture of flavone and aurone in base, whilst in acid only the flavone is observed.In contrast with recent theoretical studies, the base-catalysed results appear to conform to Baldwin's original proposal of acute-angle approach of a nucleophile to a triple bond.
- Brennan, Colin M.,Johnson, David C.,McDonnell Peter D.
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p. 957 - 962
(2007/10/02)
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- REACTIONS OF 3-ARYL-1--2-PROPYN-1-ONES IN THE PRESENCE OF AMINES. TWO TYPES OF INTRAMOLECULAR CYCLIZATION INVOLVING THE ortho-HYDROXYL GROUP
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Amines react with 3-aryl-1--2-propyn-1-ones in three directions, i.e., with addition of the reagent at the triple bond (and the formation of the β-aminovinyl ketone) and intramolecular cyclization leading to the formation of six-membered (flavones) or five-membered (aurones) heterocycles.The development of these reaction paths is controlled by the nature of the amines.Probable reaction paths are proposed.
- Korshunov, S. P.,Korzhova, N. V.,Kazantseva, V. M.,Krasnov, V. L.,Utekhina, N. V.,Bodrikov, I. V.
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p. 1658 - 1663
(2007/10/02)
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