- Synthesis and evaluation of novel prenylated chalcone derivatives as anti-leishmanial and anti-trypanosomal compounds
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Abstract Chalcones form a class of compounds that belong to the flavonoid family and are widely distributed in plants. Their simple structure and the ease of preparation make chalcones attractive scaffolds for the synthesis of a large number of derivatives enabling the evaluation of the effects of different functional groups on biological activities. In this Letter, we report the successful synthesis of a series of novel prenylated chalcones via Claisen-Schmidt condensation and the evaluation of their effect on the viability of the Trypanosomatidae parasites Leishmania amazonensis, Leishmania infantum and Trypanosoma cruzi.
- Passalacqua, Thais Gaban,Dutra, Luiz Antonio,De Almeida, Letícia,Velásquez, Angela Maria Arenas,Torres Esteves, Fabio Aurelio,Yamasaki, Paulo Renato,Dos Santos Bastos, Mariana,Regasini, Luis Octavio,Michels, Paul A.M.,Da Silva Bolzani, Vanderlan,Graminha, Marcia A.S.
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- SYNTHESIS OF (2,4,6-CYCLOHEPTATRIEN-1-YLIDENE)METHYL TRIPHENYLPHOSPHONIUM TETRAFLUOROBORATE: A STRONGLY STABILIZED YLIDE ?
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The synthesis of (cycloheptatrienylmethyl)triphenylphosphonium tetrafluoroborates is reported.Hydride abstraction to the corresponding tropylium salt followed by proton abstraction afforded the title compound IIIa which shows little, if any, ylidic charachter.
- Cavicchio, G.,Gaudiano, G.,Ponti, P. P.
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- Solvent-free synthesis of 4-chalcogenophosphorylpyridines via SN HAr reaction of pyridines with secondary phosphine chalcogenides
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Solvent- and catalyst-free synthesis of 4-chalcogenophosphorylpyridines by oxidative regioselective cross-coupling of pyridines with secondary phosphine chalcogenides using 1,3-diphenylprop-2-yn-1-one as a trigger and oxidant under mild conditions (70–75°C, 5.5–7 h) is reported.
- Volkov, Pavel A.,Ivanova, Nina I.,Khrapova, Kseniya O.,Telezhkin, Anton A.,Borodina, Tatyana N.,Gusarova, Nina K.,Trofimov, Boris A.
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- Iron-Catalyzed ?±,?-Dehydrogenation of Carbonyl Compounds
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An iron-catalyzed α,β-dehydrogenation of carbonyl compounds was developed. A broad spectrum of carbonyls or analogues, such as aldehyde, ketone, lactone, lactam, amine, and alcohol, could be converted to their α,β-unsaturated counterparts in a simple one-step reaction with high yields.
- Zhang, Xiao-Wei,Jiang, Guo-Qing,Lei, Shu-Hui,Shan, Xiang-Huan,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 1611 - 1615
(2021/03/03)
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- Combined 3D-QSAR and docking analysis for the design and synthesis of chalcones as potent and selective monoamine oxidase B inhibitors
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Monoamine oxidases (MAOs) are important targets in medicinal chemistry, as their inhibition may change the levels of different neurotransmitters in the brain, and also the production of oxidative stress species. New chemical entities able to interact selectively with one of the MAO isoforms are being extensively studied, and chalcones proved to be promising molecules. In the current work, we focused our attention on the understanding of theoretical models that may predict the MAO-B activity and selectivity of new chalcones. 3D-QSAR models, in particular CoMFA and CoMSIA, and docking simulations analysis have been carried out, and their successful implementation was corroborated by studying twenty-three synthetized chalcones (151–173) based on the generated information. All the synthetized molecules proved to inhibit MAO-B, being ten out of them MAO-B potent and selective inhibitors, with IC50 against this isoform in the nanomolar range, being (E)-3-(4-hydroxyphenyl)-1-(2,2-dimethylchroman-6-yl)prop-2-en-1-one (152) the best MAO-B inhibitor (IC50 of 170 nM). Docking simulations on both MAO-A and MAO-B binding pockets, using compound 152, were carried out. Calculated affinity energy for the MAO-A was +2.3 Kcal/mol, and for the MAO-B was ?10.3 Kcal/mol, justifying the MAO-B high selectivity of these compounds. Both theoretical and experimental structure–activity relationship studies were performed, and substitution patterns were established to increase MAO-B selectivity and inhibitory efficacy. Therefore, we proved that both 3D-QSAR models and molecular docking approaches enhance the probability of finding new potent and selective MAO-B inhibitors, avoiding time-consuming and costly synthesis and biological evaluations.
- Mellado, Marco,González, César,Mella, Jaime,Aguilar, Luis F.,Vi?a, Dolores,Uriarte, Eugenio,Cuellar, Mauricio,Matos, Maria J.
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- Inhibition of Caco-2 and MCF-7 cancer cells using chalcones: synthesis, biological evaluation and computational study
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Cancer is the second death cause worldwide, with breast and colon cancer among the most prevalent types. Traditional treatment strategies have several side effects that inspire the development of novel anticancer agents derived from natural sources, like chalcone derivatives. For this investigation, twenty-three chalcones (4a-w) were synthesized and evaluated as antiproliferative agents against MCF-7 and Caco-2 cells, finding three and two compounds with similar or higher antiproliferative activity than daunorubicin, while only two chalcones showed better selectivity indexes than daunorubicin on MCF-7. From these results, we developed good-performance QSAR models (r > 0.850, q2>0.650), finding several structural features that could modify chalcone activity and selectivity. According to these models, chalcones 4w and 4t have high potency and selectivity against Caco-2 and MCF-7, respectively, which make them attractive candidates for hit-to-lead development of ROS-independent pro apoptotic agents.
- Aguilar, Luis F.,Coddou, Claudio,Jara-Gutierrez, Carlos,Mellado, Marco,Reyna-Jeldes, Mauricio,Villena, Joan,Weinstein-Oppenheimer, Caroline
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supporting information
(2021/10/02)
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- Active Base Hybrid Organosilica Materials based on Pyrrolidine Builder Units for Fine Chemicals Production
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The catalytic activity of “pyrrolidine type” fragments included or anchored in the mesoporous silica supports or polymeric frameworks have been fully reported for enantioselective transformation. Nevertheless, low attention was focused on their catalytic abilities to perform base-catalyzed reaction. Accordingly, hybrid materials including pyrrolidine fragments in the mesoporous silica supports were prepared following different synthesis methods, such as micellar and fluoride sol-gel routes in absence of structural directing agents. Their great catalytic performance was explored for various base-catalyzed reactions to the formation of C?C bond through Knoevenagel, Claisen-Schmidt and Henry condensations under microwave irradiation. The benefits of microwave irradiation combined with suitable catalytic properties of pyrrolidine hybrid materials with strong base sites and high accessibility to active centers, allowed carrying out successfully base-catalyzed condensation reactions for the production of fine chemicals. Moreover, the hybrid catalyst exhibited high selectivity and good stability over different catalytic cycles contributing to environmental sustainability.
- Llopis, Sebastián,Velty, Alexandra,Díaz, Urbano
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p. 5012 - 5024
(2021/10/19)
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- Molecular recognition of synthesized halogenated chalcone by calf thymus DNA through multispectroscopic studies and analysis the anti-cancer, anti-bacterial activity of the compounds
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The present study aims to elucidate the anti-cancer, antimicrobial activity of synthesized halogenated chalcones (1f, 1h, 1i) and their molecular interaction with calf thymus DNA. All the three compounds were characterized using different spectroscopic tools like FTIR, NMR. DFT and TDDFT computation were performed to support the structural and electronic parameter of the compounds. UV–vis absorbance, steady-state fluorescence, time-resolved fluorescence, circular dichroism, helix melting, molecular docking study reveals that the compounds (1f, 1h, 1i) actively interact with ctDNA via groove binding mode. The binding constants (Kb) were calculated to be 1.29 × 104, 0.54 × 104 and 0.45 × 104 M?1 respectively for compounds 1f, 1h, 1i. The compounds were cytotoxic to almost every cell line (PC3, HeLa, A549, HCT116) tested, having minimal toxicity in normal NKE cell line, among which PC3 cells were more sensitive with an IC50 value of 10 μM. The values were determined using dose response curve and found between 10 and 49 μM for cancer cells and 70 μM for normal cell. Compounds also cause apoptosis in PC3 cells, which was confirmed by Annexin V-FITC/PI assay. Results showed that 1f, 1h, 1i target DNA, to persuade DNA damage mediated cancer cell death. The inhibition zone was formed in the screening test indicating the anti-bacterial activity of 1f, 1h & 1i against model pathogenic bacteria. So the present communication provides quantitative insight of halo-chalcone based anti-cancerous and antimicrobial molecule involving relevant target nucleic acid, which holds future promise in the development of new therapeutic agents.
- Ghosh, Sudipta,Ghosh, Suvranil,Mahato, Sachinta,Majee, Adinath,Mukherjee, Abhijit,Pal, Mahadeb,Sen, Sukanta Kumar,Singh, Bula
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- A new method for the synthesis of chalcone derivatives promoted by PPh3/I2under non-alkaline conditions
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A straightforward and general method has been developed for the synthesis of chalcone derivatives by a Claisen-Schmidt reaction in the presence of PPh3/I2 in 1,4-dioxane under reflux temperatures. With the condensation of the aromatic ketone and aldehyde occurring at non-strongly alkaline conditions, our proposed method significantly expands the range of applicable substrates, especially for groups that are unstable under alkaline conditions.
- Xue, Kangsheng,Sun, Guoxiang,Zhang, Yanzhi,Chen, Xubing,Zhou, Yang,Hou, Jinjun,Long, Huali,Zhang, Zijia,Lei, Min,Wu, Wanying
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supporting information
p. 625 - 634
(2020/11/23)
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- Reaction rate differences between organotrifluoroborates and boronic acids in BINOL-catalyzed conjugate addition to enones
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Enantioselective organocatalysis has been successfully employed in combination with trifluoroborate reagents for novel organic transformations over the last decade. However, no experimental rate studies of these reactions have been reported. Herein we report Hammett plot analysis of the organocatalyzed enantioselective conjugate addition of alkenyl, aryl, and heteroaryl trifluoroborate salts to chalcone derivatives with substitution at both the β-aryl and keto-aryl positions. The rate trend for keto-aryl substitution diverges from that of boronic acid nucleophiles in that the keto-aryl substituent for trifluoroborate salts does not measurably impact reaction rate in a manner consistent with charge stabilization. In addition, variable temperature NMR in combination with quantitative thin-layer chromatography (TLC) analysis suggests that the reaction is impacted by the low solubility of the trifluoroborate salts, so particle size and stirring speed affect reaction rates.
- Brooks, Bailey,Hiller, Noemi,May, Jeremy A.
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supporting information
(2021/09/28)
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- C3 amino-substituted chalcone derivative with selective adenosine rA1 receptor affinity in the micromolar range
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Abstract: To identify novel adenosine receptor (AR) ligands based on the chalcone scaffold, herein the synthesis, characterization and in vitro and in silico evaluation of 33 chalcones (15–36 and 37–41) and structurally related compounds (42–47) are reported. These compounds were characterized by radioligand binding and GTP shift assays to determine the degree and type of binding affinity, respectively, against rat (r) A1 and A2A ARs. The chalcone derivatives 24, 29, 37 and 38 possessed selective A1 affinity below 10?μM, and thus, are the most active compounds of the present series; compound 38 was the most potent selective A1 AR antagonist (Ki (r) = 1.6?μM). The structure–affinity relationships (SAR) revealed that the NH2-group at position C3 of ring A of the chalcone scaffold played a key role in affinity, and also, the Br-atom at position C3′ on benzylidene ring B. Upon in vitro and in silico evaluation, the novel C3 amino-substituted chalcone derivative 38—that contains an α,?-unsaturated carbonyl system and easily allows structural modification—may possibly be a synthon in future drug discovery. Graphic abstract: C3 amino-substituted chalcone derivative (38) with C3′ Br substitution on benzylidene ring B possesses selective adenosine rA1 receptor affinity in micromolar range.[Figure not available: see fulltext.]
- Janse van Rensburg, Helena D.,Legoabe, Lesetja J.,Terre’Blanche, Gisella
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p. 1581 - 1605
(2020/11/20)
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- Ag2CO3-catalyzed efficient synthesis of internal or terminal propargylicamines and chalcones via A3-coupling under solvent-free condition
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Several simple, fast and practical protocols have been developed to synthesize internal or terminal propargylamines and chalcones via A3-coupling reaction of aldehydes, amines, and alkynes catalyzed by an easily available catalyst Ag2CO3 under solvent-free condition. The reaction proceeded smoothly to deliver various products in good-to-excellent yields with good functional group tolerance. Gram-scale preparation, bioactive molecule synthesis and asymmetric substrates have been demonstrated. Furthermore, plausible mechanisms for the synthesis of different products have been proposed.
- Li, Ningbo,Liang, Zhiwu,Qiao, Jie,Wang, Xueyan,Xu, Li,Xu, Shitang,Xu, Xinhua
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- Green method for high-selectivity synthesis of chalcone compounds
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Under the condition of air, the water-soluble inorganic weak base is used as a catalyst to catalyze the hydrogen transfer reaction of the propargyl alcohol compound, so that the green synthesis of the high-trans selective chalcone compound is realized. Reaction temperature: 80 - 120 °C and reaction time 12 - 48 hours. To the technical scheme, any transition metal catalyst and ligand do not need to be used, inert gas protection is not needed, no other byproducts are generated, the atom economy 100%, green and environment friendliness are avoided, and the product is a high-selectivity (E)-type product. The reaction conditions are relatively low in requirement. Compared with the prior art, the alkali catalyst is obvious in advantages, and has a certain application prospect in the fields of organic synthesis, biochemistry, medicine and the like.
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Paragraph 0027-0030
(2021/10/02)
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- K2S2O8activation by glucose at room temperature for the synthesis and functionalization of heterocycles in water
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While persulfate activation at room temperature using glucose has primarily been focused on kinetic studies of the sulfate radical anion, the utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated selected K2S2O8-mediated known organic reactions that invariably require higher temperatures and an organic solvent. A diverse, mild functionalization and synthesis of heterocycles using the inexpensive oxidant K2S2O8 in water at room temperature is reported, demonstrating the sustainability and broad scope of the method. Unlike traditional methods used for persulfate activation, the current method uses naturally abundant glucose as a K2S2O8 activator, avoiding the use of higher temperature, UV light, transition metals or bases.
- Hunjan, Mandeep Kaur,Laha, Joydev K.
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p. 8437 - 8440
(2021/09/02)
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- GPR52 Antagonist Reduces Huntingtin Levels and Ameliorates Huntington's Disease-Related Phenotypes
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GPR52 is an orphan G protein-coupled receptor (GPCR) that has been recently implicated as a potential drug target of Huntington's disease (HD), an incurable monogenic neurodegenerative disorder. In this research, we found that striatal knockdown of GPR52 reduces mHTT levels in adult HdhQ140 mice, validating GPR52 as an HD target. In addition, we discovered a highly potent and specific GPR52 antagonist Comp-43 with an IC50 value of 0.63 μM by a structure-activity relationship (SAR) study. Further studies showed that Comp-43 reduces mHTT levels by targeting GPR52 and promotes survival of mouse primary striatal neurons. Moreover, in vivo study showed that Comp-43 not only reduces mHTT levels but also rescues HD-related phenotypes in HdhQ140 mice. Taken together, our study confirms that inhibition of GPR52 is a promising strategy for HD therapy, and the GPR52 antagonist Comp-43 might serve as a lead compound for further investigation.
- Wang, Congcong,Zhang, Yu-Fang,Guo, Shimeng,Zhao, Quan,Zeng, Yanping,Xie, Zhicheng,Xie, Xin,Lu, Boxun,Hu, Youhong
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p. 941 - 957
(2020/11/30)
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- Dehydrative allylation of P-H species under metal-free conditions
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An environmentally benign protocol for C-P bond construction was developed under metal- and solvent-free conditions. In the presence of B(C6F5)3, wide-spectrum P-H species, including dialkylphosphite, hypophosphite ester,
- Yang, Xiaobo,Li, Bowen,Xing, Huicong,Qiu, Ju,Loh, Teck-Peng,Xie, Peizhong
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supporting information
p. 1633 - 1637
(2021/03/09)
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- Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
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Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
- Liu, Xin,Werner, Thomas
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p. 1096 - 1104
(2020/12/31)
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- Direct Access to α,β-Unsaturated Ketones via Rh/MgCl2-Mediated Acylation of Vinylsilanes
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We report herein the facile and practical construction of α,β-unsaturated ketones via rhodium-catalyzed direct acylation of vinylsilanes with readily available and abundant carboxylic acids. This protocol features access to a diverse array of synthetically useful functionalities with moderate to excellent yields. More importantly, the late-stage functionalization of pharmaceuticals was also realized with synthetically useful yield.
- Chen, Zi-Yan,Deng, Xue-Zu,Song, Yang,Xue, Fei,Yamane, Motoki,Yue, Yan-Ni
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p. 12693 - 12704
(2021/09/28)
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- Synthesis of Ketones by C?H Functionalization of Aldehydes with Boronic Acids under Transition-Metal-Free Conditions
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A method for the synthesis of ketones from aldehydes and boronic acids via a transition-metal-free C?H functionalization reaction is reported. The method employs nitrosobenzene as a reagent to drive the simultaneous activation of the boronic acid as a boronate and the activation of the C?H bond of the aldehyde as an iminium species that triggers the key C?C bond-forming step via an intramolecular migration from boron to carbon. These findings constitute a practical, scalable, and operationally straightforward method for the synthesis of ketones.
- Roscales, Silvia,Csáky, Aurelio G.
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supporting information
p. 8728 - 8732
(2021/03/16)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Ligand-Free Palladium-Catalyzed Carbonylative Suzuki Couplings of Vinyl Iodides with Arylboronic Acids under Substoichiometric Base Conditions
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A ligand-free palladium-catalyzed carbonylation of vinyl iodides with arylboronic acids, permitting the synthesis of chalcones and α-branched enones, has been established. This reaction proceeds smoothly at ambient pressure and temperature, and works well even with a substoichiometric amount of base. Importantly, this mild, efficient, and operationally simple protocol is suitable for the late-stage functionalization of an epiandrosterone-derived complex molecule.
- Yang, Zhiyuan,Gong, Pei-Xue,Chen, Junjie,Zhang, Jie,Gong, Xu,Han, Wei
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supporting information
p. 1207 - 1212
(2021/06/18)
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- Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis
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The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.
- Zhou, Min-Jie,Zhang, Lei,Liu, Guixia,Xu, Chen,Huang, Zheng
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supporting information
p. 16470 - 16485
(2021/10/20)
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- Orchestrating a β-Hydride Elimination Pathway in Palladium(II)-Catalyzed Arylation/Alkenylation of Cyclopropanols Using Organoboron Reagents
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The scope of chemoselective β-hydride elimination in the context of arylation/alkenylation of homoenolates from cyclopropanol precursors using organoboronic reagents as transmetalation coupling partners was examined. The reaction optimization paradigm revealed a simple ligand-free Pd(II) catalytic system to be most efficient under open air conditions. The preparative scope, which was investigated with 48 examples, supported the applicability of this reaction to a wide range of substrates tolerating a variety of functional groups while delivering β-substituted enone and dienone derivatives in 62-95% yields.
- Ilangovan, Andivelu,Ramar, Thangeswaran,Subbaiah, Murugaiah A. M.
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- Divergent Synthesis of Vinyl-, Benzyl-, and Borylsilanes: Aryl to Alkyl 1,5-Palladium Migration/Coupling Sequences
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Organosilicon compounds have been extensively utilized both in industry and academia. Studies on the syntheses of diverse organosilanes is highly appealing. Through-space metal/hydrogen shifts allow functionalization of C?H bonds at a remote site, which are otherwise difficult to achieve. However, until now, an aryl to alkyl 1,5-palladium migration process seems to have not been presented. Reported herein is the remote olefination, arylation, and borylation of a methyl group on silicon to access diverse vinyl-, benzyl-, and borylsilanes, constituting a unique C(sp3)?H transformation based on a 1,5-palladium migration process.
- Han, Jie-Lian,Ju, Cheng-Wei,Qin, Ying,Zhao, Dongbing
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p. 6555 - 6560
(2020/03/03)
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- 1,2,4-Triphenylpyrroles: Synthesis, Structure and Luminescence Properties
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Pyrroles are widely found in natural products and play an important role in biological processes. Certain pyrrole derivatives are fluorescent and may be used as molecular probes or biomarkers in the diagnosis of diseases, such as Alzheimer's or Parkinson'
- Ferreira, Joana R. M.,Guieu, Samuel,Nunes Da Silva, Raquel,Rocha, Jo?o,Silva, Artur M. S.
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supporting information
p. 632 - 634
(2020/03/27)
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- Second harmonic generation in pyrazoline derivatives of dibenzylideneacetones and chalcone: A combined experimental and theoretical approach
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In this work, we investigate theoretically and experimentally second harmonic generation (SHG) in three pyrazoline compounds, being two derivatives of dibenzylideneacetone (DBA) (C23H20N2 and C25H24N2O2) and one derivative of chalcone (C21H18N2). The compounds were synthesized after two steps employing a Claisen-Schmidt condensation followed by an addition-elimination reaction with phenylhydrazine. All compounds were characterized using NMR, FT-IR, UV-Vis, and XRD. We calculated the first-order hyperpolarizabilities of these molecules using program packages based on the time-dependent Hartree-Fock (TDHF) and density functional theory (DFT). SHG was characterized by Kurtz and Perry's powder method. We observed that these organic crystals present SHG efficiencies up to 5 times larger than the KDP, and we associated these values to their molecular structure and crystalline arrangements. The values obtained experimentally and theoretically evidence that these compounds have good potential for application in electronic devices based on second-order nonlinear responses.
- de Araújo, Raiane Sodré,de Alcantara, Aline Moreira,Abeg?o, Luis M.G.,de Souza, Yago Pereira,Brand?o Silva, Ant?nio Carlos,Machado, Rogério,Joatan Rodrigues, José,Rodriguez Pliego, Josefredo,d'Errico, Francesco,Siqueira Valle, Marcelo,de Alencar, Márcio André Rodrigues Cavalcanti
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- Synthesis and characterization of 1,3,5-triarylpyrazol-4-ols and 3,5-diarylisoxazol-4-ols from chalcones and theoretical studies of the stability of pyrazol-4-ol toward acid dehydration
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The synthesis of diverse pyrazol-4-ol and isoxazole-4-ol heterocycles involving only 3 reaction steps is reported in this study. However, the synthesis of carboxamide pyrazol-4-ol has failed in the conditions used in the synthesis, acid methanol solution. The carboxamide pyrazol-4-ol decomposes via dehydration, forming the respective pyrazol. Theoretical calculations were used to elucidate the dehydration reaction. We have found a mechanism for acid-catalyzed dehydration that can explain the experimental observations. The calculated free energy profile for acid-catalyzed dehydration of the carboxamide pyrazol-4-ol and phenylpyrazole-4-ol point out that the latter is more stable in relation dehydration, with a dehydration rate 100 times smaller in acid methanol solution.
- Cipagauta Esquivel, Edna Carolina,Rufino, Virgínia Camila,Trindade Nogueira, Matheus Henrique,Carbonaro Souza, Ana Carolina,Pliego Júnior, Josefredo Rodriguez,Valle, Marcelo Siqueira
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- DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
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A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondary propargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer-Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy, and excellent yields are among the prominent features of the reaction. Additionally, the photophysical properties and crystal-structure-packing behavior of selected compounds were investigated and found to be of interest.
- De, Rimpa,Savarimuthu, Antony,Ballav, Tamal,Singh, Pijush,Nanda, Jayanta,Hasija, Avantika,Chopra, Deepak,Bera, Mrinal K.
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p. 1587 - 1592
(2020/08/28)
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- [Rh(Cod)Cl]2/Pph3?catalyzed dehydrogenative silylation of styrene derivatives with NBE as a hydrogen acceptor
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Direct synthesis of arylalkenylsilanes by [Rh(COD)Cl]2/ PPh3-catalyzed dehydrogenative silylation of styrene derivatives with R3SiH (R = alkyl, alkoxy, aryl) was realized, in which norbornene (NBE) and PPh3 play a key role in achieving excellent selectivity in the formation of dehydrogenative silylation products. Moreover, this high-yielding transformation exhibits a broad substrate scope and good functional group tolerance.
- Li, Chengyang,Lu, Wenkui,Wu, Xiaoyu,Xie, Xiaomin,Zhang, Zhaoguo
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p. 3780 - 3788
(2020/11/23)
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- 1,3-Diphenyldisiloxane Enables Additive-Free Redox Recycling Reactions and Catalysis with Triphenylphosphine
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The recently reported chemoselective reduction of phosphine oxides with 1,3-diphenyldisiloxane (DPDS) has opened up the possibility of additive-free phosphine oxide reductions in catalytic systems. Herein we disclose the use of this new reducing agent as an enabler of phosphorus redox recycling in Wittig, Staudinger, and alcohol substitution reactions. DPDS was successfully utilized in ambient-temperature additive-free redox recycling variants of the Wittig olefination, Appel halogenation, and Staudinger reduction. Triphenylphosphine-promoted catalytic recycling reactions were also facilitated by DPDS. Additive-free triphenylphosphine-promoted catalytic Staudinger reductions could even be performed at ambient temperature due to the rapid nature of phosphinimine reduction, for which we characterized kinetic and thermodynamic parameters. These results demonstrate the utility of DPDS as an excellent reducing agent for the development of phosphorus redox recycling reactions.
- Buonomo, Joseph A.,Cole, Malcolm S.,Eiden, Carter G.,Aldrich, Courtney C.
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p. 3583 - 3594
(2020/09/15)
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- IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild reaction conditions
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An efficient, practical and facile procedure has been developed for the oxidation of primary and secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature. The reaction affords quantitative yields of the corresponding carbonyl compounds without the formation of over oxidized products. The present synthetic protocol is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. The developed synthetic protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 g scale in higher yields by a simple filtration process.
- Kumar, Kamlesh,Kumar, Prashant,Joshi, Penny,Rawat, Diwan S
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supporting information
(2020/03/04)
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- Palladium-Catalyzed Amide N-C Hiyama Cross-Coupling: Synthesis of Ketones
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N-Acylglutarimides and arylsiloxanes reacted in the presence of Pd(OAc)2/PCy3, Et3N·3HF, and LiOAc to provide the corresponding arylketones in good yields. Aryl-, vinyl-, and alkyl-substituted N-acylglutarimides showed good activity in the coupling reactions of arylsiloxanes. The reaction had a broad substrate scope and showed good functional group tolerance. N-Benzoylsuccinimide and N-protected N-phenylbenzamides showed good activities in coupling reactions with phenylsiloxane. The employment of CuF2 as an activor afforded the decarbonylative products at 160 °C.
- Idris, Muhammad Aliyu,Lee, Sunwoo
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supporting information
p. 9190 - 9195
(2020/11/18)
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- Chemoselective Synthesis and Evaluation of β-Oxovinylarsines as an Arsenic Synthetic Precursor
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β-Oxovinylarsines are introduced as a stable and highly functionalized bench-top arsenic precursor. Stereoselective syntheses furnished geometrically pure cis- A nd trans-isomers from the same ynone under different conditions. The organic Michael acceptor backbone allowed β-oxovinylarsines to be easily applied to conjugate-addition reactions, and β-oxovinylarsines were reactive to nucleophiles, electrophiles, and transition metals. Unlike other arsenic precursors which are toxic or volatile or have low reactivity, β-oxovinylarsines bear a well-defined organic backbone that confers both stability and known reactivity. Remarkably, β-oxovinylarsines were also compatible with organometallic catalysts and did not decompose or deactivate the catalyst by chelation.
- Tay, Wee Shan,Li, Yongxin,Lu, Yunpeng,Pullarkat, Sumod A.,Leung, Pak-Hing
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p. 271 - 278
(2020/01/31)
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- 1,2-Diethoxyethane catalyzed oxidative cleavage of gem-disubstituted aromatic alkenes to ketones under minimal solvent conditions
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Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention, but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas. By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant, an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.
- Liu, Kai-Jian,Deng, Ji-Hui,Zeng, Tang-Yu,Chen, Xin-Jie,Huang, Ying,Cao, Zhong,Lin, Ying-Wu,He, Wei-Min
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p. 1868 - 1872
(2020/01/31)
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- Palladium anchored on guanidine-terminated magnetic dendrimer (G3-Gu-Pd): An efficient nano-sized catalyst for phosphorous-free Mizoroki-Heck and copper-free Sonogashira couplings in water
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In this research, a novel type of Fe3O4&at;silica-supported dendrimer capped by guanidine groups for immobilization of palladium was reported. This novel nano-sized catalyst was characterized by FTIR, TGA, XRD, FESEM, EDX, VSM, XPS and HRTEM methods. Enhanced catalytic activity of the prepared catalyst in Mizoroki-Heck and copper-free Sonogashira coupling reactions were evaluated in water as a green solvent. The influence of the various reaction parameters such as catalyst dosage, time and temperature on two mentioned C–C coupling reactions were studied. Results showed that the catalyst could be easily recovered by simple separation by an external magnet and reused for five cycles of recovery without considerable losing of its activity.
- Khalafi-Nezhad, Ali,Moaddeli, Ali,Niknam, Esmaeil
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- Gold-catalyzed partial hydrogenation of activated alkynes mediated by triphenylphosphine
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Gold(I) can exhibit a cooperative effect with triphenylphosphine, accelerating the triphenylphosphine-mediated partial hydrogenation of activated alkynes. In this protocol, 3-arylpropiolates are selectively reduced to the Z -isomer when the aryl ring bears an electron-donor substituent, whereas 3-arylpropynones are reduced to the E-isomers.
- Cocoletzi-Xochitiotzi, Ana Patricia,Hernández-Hernández, Miguel,Medina-Mercado, Ignacio,Jiménez-Martínez, Williams De Jesús,Mastranzo, Virginia Maricela,Porcel, Susana
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supporting information
p. 2379 - 2386
(2020/08/19)
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- Atomically precise palladium nanocluster catalyzed tandem oxidation processes of alcohols and phosphorous ylides: Facile access to α,β-unsaturated esters
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The mesoporous silica nanosphere supported palladium nanocluster was synthesized through a simple impregnation method and well characterized. The as prepared catalyst shows excellent catalytic performance in tandem oxidation process (TOP) of alcohol and phosphorous ylide, which provides an efficient access to α,β-unsaturated esters with high yields utilizes 1 atmosphere of molecular oxygen as sole oxidant. This work represents the first example of atomically precise palladium nanocluster catalyzed tandem oxidation process of alcohol and phosphorous ylide and is expected to open new horizons for nanoclusters in the tandem reactions.
- Gao, Taiping,Du, Jialei,Liu, Wenyan,Ren, Mingxia
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supporting information
(2020/09/17)
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- An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- And Stereoselective Semihydrogenation of Internal and Terminal Alkynes
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The catalytic utility of [RuL1(CO)2I2] (1), containing an annelated π-conjugated imidazo-naphthyridine-based mesoionic carbene (MIC) ligand (L1), is evaluated for E-selective alkyne semihydrogenation. The precatalyst 1, in combination with 2 equiv of AgBArF, semihydrogenates a broad range of internal alkynes with molecular hydrogen (5 bar) in water. (E)-Alkenes are accessed in high yields, and a number of reducible functional groups are tolerated. A chelate MIC ligand and two cis carbonyls provide a well-defined platform at the Ru center for hydrogenation and isomerization. The loss of two iodides and the presence of two carbonyls render the Ru center electron deficient and thus the formation of metal vinylidenes with terminal alkynes is avoided. This is leveraged for the semihydrogenation of terminal alkynes by the same catalytic system in isopropyl alcohol. Reaction profile, isomerization, kinetic, and DFT studies reveal initial alkyne hydrogenation to a (Z)-alkene, which further isomerizes to an (E)-alkene via metal-catalyzed Z → E isomerization.
- Bera, Jitendra K.,Choudhury, Joyanta,Das, Shubhajit,Dutta, Indranil,Pati, Swapan K.,Saha, Sayantani,Yadav, Suman
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p. 3212 - 3223
(2020/10/02)
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- Design, and facile synthesis of 1,3 diaryl-3-(arylamino)propan-1-one derivatives as the potential alpha-amylase inhibitors and antioxidants
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Diabetes is the most prevalent metabolic disorder causing a high rate of mortality and morbidity. Recently alpha-amylase is reported to be good drug design target for the treatment of diabetes mellitus. We have designed 116 molecules based on aza-Michael
- Bashary, Roqia,Khatik, Gopal L.
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p. 156 - 162
(2018/10/20)
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- Studies of NMR Chemical Shifts of Chalcone Derivatives of Five-membered Monoheterocycles and Determination of Aromaticity Indices
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A series of the chalcone derivatives of the five-membered monoheterocyclic compounds, (E)-1-aryl-3-heteroarylpropen-1-ones, were prepared by aldol condensation of the corresponding aldehydes of thiophene, pyrrole, and furan with m- and p-substituted acetophenones. Similar condensation of the acetyl compounds of the heterocycles with m- and p-substituted benzaldehydes gave another series of the chalcone derivatives, (E)-1-heteroaryl-3-arylpropen-1-ones. The 13C chemical shift values (δC) of the chalcone derivatives were determined in order to find if they correlated with the Hammett σ values. A good correlation, especially for the β-C for both series, was found for the 13C chemical shift values (δC) of the chalcone derivatives with the Hammett σ values. The chemical shift values of the β-C of the heterocyclic compounds were plotted against those of the benzene derivatives. The resulting slopes were found to be close to the values of the aromaticity indices.
- Jeong, Eun Jeong,Lee, In-Sook Han
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p. 668 - 673
(2019/07/12)
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- Synthesis and characterization of co-doped fly ash catalyst for chalcone synthesis
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A series of solid base fly ash hybrid materials were synthesized by doping alkali, alkaline earth metals with nitrogen, separately using co-precipitation process, combined with surfactant incorporating method. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and photoluminescence spectroscopy. Results revealed that the co-doped hybrid materials are highly stable with particle size in the range of 40-60 nm. The surface basicity of fly ash was upraised by increased hydroxyl content by doping with alkali, alkaline earth metals with nitrogen. The basicity of hybrid material was measured by liquid phase, solvent free, single step condensation of 4-chlorobenzaldehyde and acetophenone giving higher conversion rate and selectivity of desired product chalcone. This conversion showed that the fly ash based hybrid material has sufficient basic site, responsible for the catalytic activity.
- Ghoshir,Kande,Muley,Gambhire
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p. 2165 - 2172
(2019/09/03)
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- Organocatalytic asymmetric vinylogous 1,4-addition of α,α-Dicyanoolefins to chalcones under a bio-based reaction media: Discovery of new Michael adducts with antiplasmodial activity
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The organocatalysed asymmetric vinylogous Michael addition of α,α-dicyanoolefins to α,β-unsaturated aldehydes and ketones have been reported in the last decade, however, chalcones have been poorly explored. Moreover, a considerable part of the publications in this theme still employs undesirable solvents, such as toluene and THF, with concerns related to health and environmental safety. We report herein the use of a bifunctional catalyst derived from a Cinchona alkaloid to perform the enantio- and diastereoselective Michael addition of α,α-dicyanoolefins to chalcones using 2-MeTHF as solvent. The Michael adducts were obtained in moderate to good yields and were evaluated for their antiplasmodial and cytotoxic activity.
- Martelli, Lorena S.R.,Vieira, Lucas C.C.,Paix?o, Márcio W.,Zukerman-Schpector, Julio,de Souza, Juliana O.,Aguiar, Anna Caroline C.,Oliva, Glaucius,Guido, Rafael V.C.,Corrêa, Arlene G.
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supporting information
p. 3530 - 3542
(2019/05/24)
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- Synthesis of 4,5,6,7-tetrahydrobenzoxazol-2-ones by a highly regioselective Diels-Alder cycloaddition of exo-oxazolidin-2-one dienes with chalcones
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The synthesis of novel of 4,5,6,7-tetrahydrobenzoxazol-2-ones is herein reported. They were obtained in moderate to good yields by a highly regio- and stereoselective Diels-Alder cycloaddition of N-substituted exo-oxazolidin-2-one dienes with chalcones or bis-chalcones as dienophiles.
- Mastachi-Loza, Salvador,Ramírez-Candelero, Tania I.,Tapia-Bustamante, Asenet,González-Romero, Carlos,Díaz-Torres, Eduardo,Tamariz, Joaquín,Toscano, Rubén A.,Fuentes-Benítes, Aydeé
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supporting information
p. 1370 - 1374
(2019/04/30)
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- Basic Anion-Exchange Resin-Catalyzed Aldol Condensation of Aromatic Ketones with Aldehydes in Continuous Flow
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A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon-carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer's drug.
- Laroche, Benjamin,Saito, Yuki,Ishitani, Haruro,Kobayashi, Shū
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supporting information
p. 961 - 967
(2019/05/02)
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- Acyl/aroyl Meldrum's acid as an enol surrogate for the direct organocatalytic synthesis of α,β-unsaturated ketones
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The operationally simple, robust and straightforward organocatalytic protocol is developed for the synthesis of E-selective α,β-unsaturated ketones. The method utilizes simple and easily accessible starting materials such as Meldrum's acid, carboxylic acid, aldehyde and simple bifunctional amine catalyst. The tandem organocatalytic process utilizes acyl/aroyl Meldrum's acid as an enol surrogate for the effective Doebner-Knoevenagel type condensation reactions. A wide variety of aldehydes, carboxylic acids and base sensitive functional groups are well tolerated under the mild reaction conditions.
- Khopade, Tushar M.,Warghude, Prakash K.,Mete, Trimbak B.,Bhat, Ramakrishna G.
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supporting information
p. 197 - 200
(2018/12/13)
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- Ligand-controlled phosphine-free Co(II)-catalysed cross-coupling of secondary and primary alcohols
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Cobalt(II) complexes (5 mol% Co) bearing phosphine-free N?N?N pincer ligands efficiently catalyze C–C coupling of secondary and primary alcohols to selectively form α-alkylated ketones with a good functional group compatibility using NaOH (20 mol%) as a base at 120 °C. The NH group on the N?N?N–Co(II) precatalyst controls the activity and selectivity. This simple catalytic system is involved in the synthesis of quinolones via the dehydrogenative annulation of 2-aminobenzyl alcohols with secondary alcohols.
- Zhang, Shi-Qi,Guo, Bin,Xu, Ze,Li, Hong-Xi,Li, Hai-Yan,Lang, Jian-Ping
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- Regioselective hydrodehalogenation of aromatic α-and β-halo carbonyl compounds by cui in isopropanol
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An operationally efficient and regioselective hydrodehalogenation methodology of aromatic α-and β-halo carbonyl compounds has been developed using CuI in isopropanol at 90 °C under basic condition. The catalytic system effectively dehalogenates chloride, bromide, and iodide groups and af-forded high yield (up to 97 %) as carbonyl compounds. The methodology is environmentally friendly and demonstrates excellent tolerance to a broad range of electronically rich and poor substituents.
- Parveen, Iram,Khan, Danish,Ahmed, Naseem
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p. 759 - 764
(2019/01/09)
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- Intermolecular Multiple Dehydrogenative Cross-Couplings of Ketones with Boronic Acids and Amines via Copper Catalysis
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An efficient and versatile oxidative coupling reaction was developed for the synthesis of valuable β-functionalized unsaturated ketones and meta-substituted phenols. In the case of intramolecular reactions, achieving rapid molecular complexity through multiple dehydrogenative couplings is already a well-established strategy. Herein, we report an intermolecular multiple dehydrogenative coupling between ketones and nucleophilic amines or boronic acids using inexpensive copper(I) oxide as a catalyst. This method provides a facile access to highly desirable chemical products such as α,β-unsaturated ketones, enaminones, and synthetically relevant meta-substituted phenols. (Figure presented.).
- Wang, Tianzhang,Chen, Guowei,Lu, Yu-Jing,Chen, Qian,Huo, Yanping,Li, Xianwei
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supporting information
p. 3886 - 3892
(2019/07/19)
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- Arylation of Aldehydes to Directly Form Ketones via Tandem Nickel Catalysis
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A nickel-catalyzed arylation of both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination.
- Lei, Chuanhu,Zhu, Daoyong,Tangcueco, Vicente Iii Tiu,Zhou, Jianrong Steve
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supporting information
p. 5817 - 5822
(2019/08/26)
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- Retro-Corey-Chaykovsky Epoxidation: Converting Geminal Disubstituted Epoxides to Ketones
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Corey-Chaykovsky epoxidation has been widely applied in the conversion of aldehydes and ketones to epoxides with sulfonium and sulfoxonium ylides. The reverse transformation is realized for conversion of geminal disubstituted epoxides to ketones in the presence of DABCO in refluxing mesitylene. The method is a weak basic transformation from epoxides to ketones with loss of a methylene group and can be applied as an alternative strategy of the acid-catalyzed Meinwald rearrangement or oxidation for conversion of epoxides to carbonyl compounds.
- Li, Siqi,Li, Pingfan,Xu, Jiaxi
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- Acylation of Alkenes with the Aid of AlCl3 and 2,6-Dibromopyridine
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Friedel-Crafts-type acylation of alkenes with acyl chlorides has been successfully conducted with a wide substrate scope by the combined use of AlCl3 and 2,6-dibromopyridine. Trisubstituted alkenes afford allylketones or vinylketones depending on the presence or absence of hydrogen atom(s) at the β-position to the acylation site, while monosubstituted alkenes exclusively afford vinylketones.
- Tanaka, Shinya,Kunisawa, Tsukasa,Yoshii, Yuji,Hattori, Tetsutaro
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supporting information
p. 8509 - 8513
(2019/11/03)
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- Oxovanadium(v)-catalyzed deoxygenative homocoupling reaction of alcohols
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Oxovanadium(v)-catalyzed transformation of alcohols in the presence of hydrazine derivatives was demonstrated. The direct hydrazination reaction of 1,3-diphenylprop-2-en-1-ol with 1,1-diphenylhydrazine in the presence of VO(OSiPh3)3 as a catalyst and MS3A as a dehydrating reagent proceeded to afford the corresponding hydrazination product. On the contrary, the utilization of 1,1-dimethylhydrazine instead of 1,1-diphenylhydrazine was found to induce the deoxygenative homocoupling reaction of the allyl alcohol to give the corresponding 1,5-diene as a major product. In addition to the deoxygenative homocoupling product, the allyl amine into which aniline was introduced was also obtained by using 1,2-diphenylhydrazine in the reaction of 1,3-diphenyl-2-methylprop-2-en-1-ol. Oxovanadium(v)-catalyzed deoxygenative homocoupling reaction of benzyl alcohols could also be performed in the presence of 1,1-dimethylhydrazine.
- Sakuramoto, Takashi,Donaka, Yosuke,Tobisu, Mamoru,Moriuchi, Toshiyuki
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p. 17571 - 17576
(2019/11/25)
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- Preparation and Application of Amino Phosphine Ligands Bearing Spiro[indane-1,2′-pyrrolidine] Backbone
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P,Nsp3-bidentate chiral ligands bearing spiro[indane-1,2′-pyrrolidine] backbone were prepared in gram scale for the first time. Pd complexes of these air-stable amino phosphine ligands could catalyze asymmetric allylic substitutions of malonate-, alcohol-, and amine-type nucleophiles in up to 97percent ee and 99percent yield. A crystal structure of [Pd(II)(η3-1,3-diphenylallyl)(ligand)]PF6 indicated possible transition states of the catalytic reactions. These ligands are characteristic of a very rigid backbone, which is simple but highly effective. They rival C2-symmetric bisphosphine, P,Nsp2-bidentate, and P,Nsp3-bidentate ligands in tested allylic substitutions. ?
- Feng, Lifei,Jiao, Peng,Li, Hongjie,Li, Shasha,Zhang, Jinxia
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p. 9460 - 9473
(2019/08/26)
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