- Diastereoselective 1,3-dioxolane formation by photocatalytic ring opening of a-epoxyketones
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Photocatalytic ring opening of α-epoxyketones by 2,3-dichloro-5,6- dicyano-1,4-benzoquinone (DDQ) in acetone resulted in the diastereoselective formation of 1,3-dioxolanes through Cα-O bond cleavage. The facility of the ring opening is influenced by the nature and the location of the additional substituent on the α-epoxyketones.
- Memarian, Hamid Reza,Zare, Sakineh
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- Synthesis of 1,4-dihydropyridazines from propargylic alcohols and hydrazones via a Cs2CO3-mediated process
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An efficient catalyst-free annulation process between propargylic alcohols and hydrazones has been reported. Under the optimized conditions, a wide variety of propargylic alcohols bearing an aromatic group or an aromatic heterocyclic group and hydrazones
- Ding, Zong-Cang,Yang, Ying,Cai, Shu-Ning,Wen, Jia-Jie,Zhan, Zhuang-Ping
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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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- 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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- 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,Xu, Shitang,Wang, Xueyan,Xu, Li,Qiao, Jie,Liang, Zhiwu,Xu, Xinhua
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p. 3993 - 3997
(2021/05/31)
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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 0071-0074
(2021/10/02)
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- Pyridoimidazole derivatives as well as preparation method and application thereof
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The invention discloses pyridoimidazole derivatives as well as a preparation method and application thereof. The pyridoimidazole derivatives with two D-pi-A structures are synthesized on the basis that pyridoimidazole serves as an electron acceptor system by means of the electron donating property of phenanthroimidazole/diphenylamine. The pyridoimidazole derivatives can serve as photoinitiators, and the two photoinitiators both have longer conjugated chain lengths, so that the photon absorption cross section is increased, the photoinitiators can initiate polymerization reaction at the wavelength of 365 nm, have higher polymerization efficiency, and can be widely applied to the field of ultraviolet curing.
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Paragraph 0093; 0097-0099
(2021/06/22)
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- Borane-Catalyzed, Chemoselective Reduction and Hydrofunctionalization of Enones Enabled by B-O Transborylation
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The use of stoichiometric organoborane reductants in organic synthesis is well established. Here these reagents have been rendered catalytic through an isodesmic B-O/B-H transborylation applied in the borane-catalyzed, chemoselective alkene reduction and formal hydrofunctionalization of enones. The reaction was found to proceed by a 1,4-hydroboration of the enone and B-O/B-H transborylation with HBpin, enabling catalyst turnover. Single-turnover and isotopic labeling experiments supported the proposed mechanism of catalysis with 1,4-hydroboration and B-O/B-H transborylation as key steps.
- Nicholson, Kieran,Langer, Thomas,Thomas, Stephen P.
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supporting information
p. 2498 - 2504
(2021/04/13)
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- Mechanochemical Syntheses of N-Containing Heterocycles with TosMIC
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A mechanochemical van Leusen pyrrole synthesis with a base leads to 3,4-disubstitued pyrroles in moderate to excellent yields. The developed protocol is compatible with a range of electron-withdrawing groups and can also be applied to the synthesis of oxazoles. Attempts to mechanochemically convert the resulting pyrroles into porphyrins proved to be difficult.
- Bolm, Carsten,Molitor, Claude,Rissanen, Kari,Schumacher, Christian,Smid, Sabrina,Truong, Khai-Nghi
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p. 14213 - 14222
(2021/09/07)
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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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- Synthesis and antimicrobial evaluation of arylated 1,3,5-triphenyl pyrazoline derivatives using suzuki-miyaura reactions
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The first palladium –catalyzed coupling reactions of 1,3,5-triphenyl pyrazoline are reported. The Suzuki-Miyaura reaction of 3-(4-bromophenyl)-1,5-diphenyl pyrazoline with one equivalent of arylboronic acids afforded 3-(biphenyl)-1,5-diphenyl pyrazoline in 53-78 % yield. While the Suzuki-Miyaura reactions of 3,5-bis(4-bromophenyl)-1-phenyl pyrazoline with two equivalent of arylboronic acids gave 3,5-bis(biphenyl)-1-phenyl pyrazoline in 55-80% yield. The characterization of the synthesized derivatives (5a-h) and (6a-h) were accomplished on the basis of NMR, FT-IR, and mass techniques. The newly pyrazoline derivatives have been investigated for their in vitro antibacterial activity against gram- negative and gram-positive bacteria. The di-coupling compounds (6a-h) exhibited promising antibacterial against all four bacterial strains compared to the mono-coupling compounds (5a-h) which displayed a slight activity. The compound 6d showed a potent activity significantly more active than Trimethoprim (100μg/ml).
- Karim, Diana Khaled,Salman, Ghazwan Ali,Al-Mansury, Sadiq,Jinzeel, Nahida Abdulla
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p. 2469 - 2481
(2021/05/11)
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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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- Biological activity of novel pentasubstituted cyclohexanol against some microorganisms
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The aim of this study is to investigate the antibacterial, antifungal activity of the new six membered 4-(4-bromophenyl)-4-hydroxy-2.6-diphenylcyclohexane-1.3-diyl)bis(4-bromophenyl)methanone and known (E)-1-(4-bromophenyl)-3phenylprop-2-en-1-one. The investigated products exhibit promising activities.
- Mamedov, I. G.,Mamedova, Y. V.
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p. 283 - 286
(2021/09/28)
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- Recyclable Copper Nanoparticles-Catalyzed Hydroboration of Alkenes and β-Borylation of α,β-Unsaturated Carbonyl Compounds with Bis(Pinacolato)Diboron
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Nano-ferrite-supported Cu nanoparticles (Fe-dopamine-Cu NPs) catalyzed anti-Markovnikov-selective hydroboration of alkenes with B2pin2 is reported under mild reaction conditions. This protocol can be applied to a broad range of substrates with high functional group compatibility. In addition, we demonstrated the use of Fe-dopamine-Cu NPs as a catalyst for the β-borylation of α,β-unsaturated ketones and ester, providing alkylboronate esters in up to 98% yield. Reuse of the magnetically recyclable catalyst resulted in no significant loss of activity in up to five reaction runs for both systems. (Figure presented.).
- Shegavi, Mahadev L.,Saini, Suresh,Bhawar, Ramesh,Vishwantha, Meghana Desai,Bose, Shubhankar Kumar
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supporting information
p. 2408 - 2416
(2021/03/16)
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- Efficient base-free asymmetric one-pot synthesis of spiro[indoline-3,3′-pyrrolizin]-2-one derivatives catalyzed by chiral organocatalyst
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A 1,3-dipolar cycloaddition reaction has been performed under organocatalytic conditions with high enantioselectivity by the utilization of bipyridine-based chiral quaternary ammonium bromide as an organocatalyst. Here, the reaction of 1,3-dipolar cycloaddition of azomethine ylide generated in situ from the decarboxylative condensation of α-amino acids and non-enolizable 1,2-diketones to the above dipolarophiles takes place.
- Chithiraikumar, Chinnadurai,Ponmuthu, Kottala Vijaya,Harikrishnan, Muniyasamy,Malini, Nelson,Sepperumal, Murugesan,Siva, Ayyanar
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p. 895 - 909
(2020/10/29)
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- Rapid umpolung Michael addition of isatin N, N ′-cyclic azomethine imine 1,3-dipoles with chalcones
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The umpolung Michael addition of isatin N,N′-cyclic azomethine imine 1,3-dipoles with chalcones is reported. The reaction could be finished within a very short time (0.3-2 min), with 3,3-disubstituted oxindole derivatives obtained in moderate to excellent yields with promising dr values. Unusual Michael adducts were obtained in moderate to high yields (26-98%) with low to high diastereoselectivities (0.8: 1 to 8.5: 1 dr). All the synthesized compounds (3, 3′, 4, 5, 5′, 7, 7′, 9 and 9′) were well characterized by FTIR, NMR, and mass spectral analyses and further confirmed by the single-crystal X-ray diffraction analysis of compounds 3aa and 4n.
- Yue, Guizhou,Jiang, Dan,Dou, Zhengjie,Li, Sicheng,Feng, Juhua,Zhang, Li,Chen, Huabao,Yang, Chunping,Yin, Zhongqiong,Song, Xu,Liang, Xiaoxia,Wang, Xianxiang,Lu, Cuifen
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supporting information
p. 11712 - 11718
(2021/07/12)
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- Asymmetric Enamide–Imine Tautomerism in the Kinetic Resolution of Tertiary Alcohols
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An efficient protocol for kinetic resolution of tertiary alcohols has been developed through an unprecedented asymmetric enamide-imine tautomerism process enabled by chiral phosphoric acid catalysis. A broad range of racemic 2-arylsulfonamido tertiary allyl alcohols could be kinetically resolved with excellent kinetic resolution performances (with s-factor up to >200). This method is particularly effective for a series of 1,1-dialkyl substituted allyl alcohols, which produced chiral tertiary alcohols that would be difficult to access via other asymmetric methods. Facile and versatile transformations of the chiral α-hydroxy imine and enamide products, especially the efficient stereodivergent synthesis of all four stereoisomers of β-amino tertiary alcohols using one enantiomer of the catalyst, demonstrated the value of this kinetic resolution method.
- Gu, Huanchao,He, Shunlong,Rajkumar, Subramani,Tang, Mengyao,Yang, Xiaoyu
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supporting information
p. 21334 - 21339
(2021/08/23)
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- Transition metal-free domino aryl-aryl coupling/phospha-Michael addition of diarylphosphinite to α,β-unsaturated ketones triggered by alkaline hydrolysis of (4-(2-alkenoyl)phenyl)triarylphosphonium salts
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Alkaline hydrolysis of a variety of (4-(2-alkenoyl)phenyl)triarylphosphonium bromides is reported. This hydrolysis triggers coupling of 4-(2-alkenoyl)phenyl with one aryl via phosphorus(V). Both diarylphosphinite and an α,β-unsaturated ketone are in situ generated and then undergo phospha-Michael addition to provide β-diarylphosphoryl ketones bearing a biaryl moiety in 27–70% yields in the absence of a transition metal.
- Huang, Wenhua,Xue, Jing-Yu
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- Potassium Base-Promoted Diastereoselective Synthesis of 1,3-Diols from Allylic Alcohols and Aldehydes through a Tandem Allylic-Isomerization/Aldol–Tishchenko Reaction
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This study reports the first base-promoted aldol–Tishchenko reactions of allylic alcohols with aldehydes initiated by allylic isomerization. The reaction enables the diastereoselective synthesis of a variety of 1,3-diols with three contiguous stereogenic centers. Unlike commonly reported systems, our method allows the use of readily available allylic alcohols as nucleophiles instead of enolizable aldehydes and ketones.
- Sai, Masahiro
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supporting information
p. 4053 - 4056
(2021/10/25)
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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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- Synthesis of 3-fluoro-2,5-disubstituted furans through ring expansion ofgem-difluorocyclopropyl ketones
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The synthesis of 3-fluoro-2,5-disubstituted furans fromgem-difluorocyclopropyl ketones was accomplished using trifluoromethanesulfonic acid (CF3SO3H) through ring expansion owing to the activation of the carbonyl group in the starting material. The present synthesis of 3-fluorofurans tolerates substrates designed for products with aromatic substituents at the C-2 and C-5 positions.
- Amii, Hideki,Matsumura, Chihori,Sugiishi, Tsuyuka
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supporting information
p. 3459 - 3462
(2020/05/25)
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- N-Heterocyclic Carbene Catalyzed Synthesis of Trisubstituted Epoxides via Tandem Amidation/Epoxidation Sequence
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A tandem amidation/epoxidation sequence between various substituted chalcones and N,N-dimethylformamide (DMF) for the synthesis of trisubstituted epoxides employing N-heterocyclic carbene catalysis was developed. This reaction was performed under metal-free conditions in the presence of tert-butyl hydroperoxide (TBHP) as the oxidant. Trisubstituted epoxides bearing a ketone and an amide functionality (N,N-dimethyl formyl group) were synthesized starting from a wide range of chalcones in moderate to good yields with excellent diastereoselectivity.
- Devi, E. Sankari,Pavithra, Thangavel,Tamilselvi,Nagarajan, Subbiah,Sridharan, Vellaisamy,Maheswari, C. Uma
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supporting information
p. 3576 - 3580
(2020/04/20)
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- Aryl-4,5-dihydro-1H-pyrazole-1-carboxamide derivatives bearing a sulfonamide moiety show single-digit nanomolar-to-subnanomolar inhibition constants against the tumor-associated human carbonic anhydrases IX and XII
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A series of new 3-phenyl-5-aryl-N-(4-sulfamoylphenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide derivatives was designed here, synthesized, and studied for carbonic anhydrase (CAs, EC 4.2.1.1) inhibitory activity against the human (h) isozymes I, II, and VII (cytosolic, off-target isoforms), and IX and XII (anticancer drug targets). Generally, CA I was not effectively inhibited, whereas effective inhibitors were identified against both CAs II (KIs in the range of 5.2-233 nM) and VII (KIs in the range of 2.3-350 nM). Nonetheless, CAs IX and XII were the most susceptible isoforms to this class of inhibitors. In particular, compounds bearing an unsubstituted phenyl ring at the pyrazoline 3 position showed 1.3-1.5 nM KIs against CA IX. In contrast, a subset of derivatives having a 4-halo-phenyl at the same position of the aromatic scaffold even reached subnanomolar KIs against CA XII (0.62-0.99 nM). Docking studies with CA IX and XII were used to shed light on the derivative binding mode driving the preferential inhibition of the tumor-associated CAs. The identified potent and selective CA IX/XII inhibitors are of interest as leads for the development of new anticancer strategies.
- Ceruso, Mariangela,Gratteri, Paola,Hargunani, Priya,Kazaks, Andris,Leitans, Janis,Nocentini, Alessio,Supuran, Claudiu T.,Tadge, Nikhil,Tars, Kaspars,Toraskar, Mrunmayee P.
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- Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Using Amide-Based Cinchona Alkaloids as Hybrid Phase-Transfer Catalysts
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A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids. Our method is characterized by low catalyst loading (0.5 mol %) and short reaction times. Moreover, the epoxidation process can be carried out in 10 cycles, without further catalyst addition to the reaction mixture. This methodology significantly enhance the scale of the process using very low catalyst loading.
- Jurczak, Janusz,Majdecki, Maciej,Tyszka-Gumkowska, Agata
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supporting information
(2020/11/13)
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- Oxidative Cyclization of Chalcones in the Presence of Sulfamic Acid as Catalyst. Synthesis, Biological Activity, and Thermal Properties of 1,3,5-Trisubstituted Pyrazoles
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Abstract: 1-Aroyl-3,5-diaryl-1H-pyrazoles weresynthesized by oxidative cyclization of chalcones with benzohydrazide and4-nitrobenzohydrazide using sulfamic acid as a catalyst. The correspondingchalcones were prepared by condensation of aromatic aldehydes with acetophenonesin PEG-400 in the presence of potassium hydroxide. Some representative featuresof the proposed procedure include exceptional regioselectivity, comparativelyshort reaction time, operational simplicity, and no need of external oxidant.The synthesized pyrazole derivatives were screened as antibacterial agentsagainst Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonellatyphi by the agar well diffusion method. Attempts were made tocompute specific heat capacity of the synthesized pyrazole derivatives as afunction of temperature using TGA–DSC in order to avail thermodynamic databasefor these biologically relevant heterocycles.
- Bhirud, J. D.,Gupta, G. R.,Narkhede, H. P.
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p. 1815 - 1822
(2020/12/01)
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- A strategy to construct multifunctional TADF materials for deep blue and high efficiency yellow fluorescent devices
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Three deep blue thermally activated delayed fluorescence (TADF) molecules are designed by connecting three different sterically hindered electron-donating groups with 2,6-diphenylpyrimidine acceptors. The rigid structures based on carbazole derivatives en
- Guo, Runda,Liu, Wei,Lv, Xialei,Sun, Shuaiqiang,Wang, Lei,Wang, Yaxiong,Ye, Shaofeng,Zhang, Qing
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supporting information
p. 4818 - 4826
(2020/04/17)
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- On the development of a nucleophilic methylthiolation methodology
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Methylthiolation reactions are usually explored to access organosulfur compounds using methanethiol, an extremely flammable and toxic compound. Herein, methylthiomethyl esters were successfully applied as novel methylthiolation reagents in a low cost, transition-metal-free methodology. These reagents allowed the methylthiolation of a wide scope of chalcones, acyl ester derivatives and Morita-Baylis-Hillman acetates with good group tolerance, affording the methylthiolated products in moderate to excellent yields. The reaction mechanism was investigated through several control experiments, as well as by theoretical calculations employing Density Functional Theory. The results strongly support that a sulfurane and a sulfonium ylide appear as key intermediates and that a Pummerer type rearrangement is also crucial for the formation of this novel reagent. Furthermore, the methylthiolation mechanism is likely to proceed through the nucleophilic attack of the reagent, followed by an entropically favoured step involving the acetate attack to the positively charged species, then releasing the product. This journal is
- Carvalho, Bernardo Basbaum Portinho De Puga,Amaral, Adriane Antonia Pereira,De Castro, Pedro P?ssa,Ferreira, Fernanda Cerqueira Moreira,Horta, Bruno Araújo Cautiero,Amarante, Giovanni Wilson
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p. 5420 - 5426
(2020/08/03)
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- Lewis acid catalyst system for Claisen-Schmidt reaction under solvent free condition
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Ca(OTf)2 in combination with NBu4.BF4 was established to function as an efficient catalyst system for one-pot Claisen-Schmidt condensation under neat conditions. Substituted acetophenones and benzaldehydes were coupled in situ to afford their corresponding chalcones in excellent yields. The method, with a broad range of substrate tolerance and mild operational conditions can produce assorted chalcone derivatives in moderate to high yields from easily accessible starting materials.
- Halpani, Chandni G.,Mishra, Satyendra
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- Donor-acceptor architectures of tetraphenylethene linked aza-BODIPYs: Synthesis, crystal structure, energy transfer and computational studies
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This work is focused on the design and synthesis of donor-acceptor pairs comprising of aza-BODIPY and tetraphenylethene (TPE) fluorogens with large pseudo Stokes shifts (386–424 nm). Femtosecond transient absorption spectroscopy, single crystal X-ray technique and TD-DFT studies were used to get more insight about their spectral behavior. As compared to the tetra-phenylaza-BODIPY, the four aza-BODIPYs exhibited 50–90 nm red shifted absoprtion and emission spectra. When the donor-acceptor architectures were excited at 300 nm, the aza-BODIPY unit emitted strong fluorescence in red region. This suggested an intramolecular energy transfer between donor (TPE) and the aza-BODIPY acceptor; with 81–90% energy transfer efficiencies. Femtosecond transient absorption studies also supported energy transfer process in the molecules, with 3.7 ps time constant associated with it. Aggregation studies in THF/n-heptane solution showed hypsochromic shifts in the aggregated form; X-ray packing structures indicated H-type aggregates (slip angle > 54.7°) in the solid state. Scanning electron microscopy (SEM) measurement revealed 200–700 nm size sphere shaped structures in the aggregated forms.
- Balsukuri, Naresh,Das, Aritra,Gupta, Iti,Lone, Mohsin Y.,Manav, Neha,Mori, Shigeki,Sen, Pratik
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- β-Carbolines: synthesis of harmane, harmine alkaloids and their structural analogs by thermolysis of 4-aryl-3-azidopyridines and investigation of their optical properties
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[Figure not available: see fulltext.] Interest in β-carbolines is caused by the biological activity of these compounds and the use of their fluorescent properties in the study of their interaction with DNA and other biological targets, as well as with drug delivery vehicles. A new general method for the synthesis of harmane, harmine, and their structural analogs by thermolysis of substituted 4-aryl-3-azidopyridines was developed, and their optical properties were studied.
- Shuvalov, Vladislav Yu.,Elisheva, Valeriya А.,Belousova, Anastasiya S.,Arshinov, Evgenii V.,Glyzdinskaya, Larisa V.,Vorontsova, Marina А.,Chernenko, Sergei А.,Fisyuk, Aleksander S.,Sagitullina, Galina P.
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- Poly-halogenated aza-bodipy dyes with improved solubility as a versatile synthetic platform for the design of photonic materials
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The optimization of the solubility in organic solvents of halogenated aza-dipyrromethenes was achieved by substitution of the upper phenyl moieties by branched long alkoxy chains (1f) or by using an OMe-OHex-OMe pattern (1h). These results allowed us to prepare original tetra-halogenated aza-dipyrromethenes that were used as a synthetic platform to access highly functionalized aza-bodipy dyes for various potential applications including PDT, imaging, or nonlinear optics. This journal is
- Andraud, Chantal,Berginc, Gérard,David, Sylvain,Maury, Olivier,Pilet, Guillaume
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p. 13125 - 13130
(2020/09/07)
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- Diversified Transformations of Tetrahydroindolizines to Construct Chiral 3-Arylindolizines and Dicarbofunctionalized 1,5-Diketones
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Enantioselective diverse synthesis of a small-molecule collection with structural and functional similarities or differences in an efficient manner is an appealing but formidable challenge. Asymmetric preparation and branching transformations of tetrahydroindolizines in succession present a useful approach to the construction of N-heterocycle-containing scaffolds with functional group, and stereochemical diversity. Herein, we report a breakthrough toward this end via an initial diastereo- A nd enantioselective [3 + 2] cycloaddition between pyridinium ylides and enones, following diversified sequential transformations. Chiral N,N′-dioxide-earth metal complexes enable the generation of optically active tetrahydroindolizines in situ, across the strong background reaction for racemate-formation. In connection with deliberate sequential transformations, involving convenient rearomatic oxidation, and light-active aza-Norrish II rearrangement, the tetrahydroindolizine intermediates were converted into the final library including 3-arylindolizine derivatives and dicarbofunctionalized 1,5-dicarbonyl compounds. More importantly, the stereochemistry of four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axial chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridged cyclic compounds were also discovered depending on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the reaction processes.
- Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Pan, Chenjing,Su, Zhishan,Wu, Zhikun,Zhang, Dong,Zhou, Yuqiao
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supporting information
p. 15975 - 15985
(2020/10/18)
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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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- 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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- 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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- 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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- Design, synthesis, and biological evaluation of novel thienopyrimidine derivatives as PI3Kα inhibitors
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Three series of novel thienopyrimidine derivatives 9a-l, 15a-l, and 18a-h were designed and synthesized, and their IC50 values against four cancer cell lines HepG-2, A549, PC-3, and MCF-7 were evaluated. Most compounds show moderate cytotoxicity against the tested cancer cell lines. The most promising compound 9a showed moderate activity with IC50 values of 12.32 ± 0.96, 11.30 ± 1.19, 14.69 ± 1.32, and 9.80 ± 0.93 μM, respectively. The inhibitory activities of compounds 9a and 15a against PI3Kα and mTOR kinase were further evaluated. Compound 9a exhibited PI3Kα kinase inhibitory activity with IC50 of 9.47 ± 0.63 μM. In addition, docking studies of compounds 9a and 15a were also investigated.
- Yu, Lide,Wang, Qinqin,Wang, Caolin,Zhang, Binliang,Yang, Zunhua,Fang, Yuanying,Zhu, Wufu,Zheng, Pengwu
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- Reaction condition controlled nickel(ii)-catalyzed C-C cross-coupling of alcohols
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The challenge in the C-C cross-coupling of secondary and primary alcohols using acceptorless dehydrogenation coupling (ADC) is the difficulty in accurately controlling product selectivities. Herein, we report a controlled approach to a diverse range of β-alkylated secondary alcohols, α-alkylated ketones and α,β-unsaturated ketones using the ADC methodology employing a Ni(ii) 4,6-dimethylpyrimidine-2-thiolate cluster catalyst under different reaction conditions. This catalyst could tolerate a wide range of substrates and exhibited a high activity for the annulation reaction of secondary alcohols with 2-aminobenzyl alcohols to yield quinolines. This work is an example of precise chemoselectivity control by careful choice of reaction conditions.
- Zhang, Meng-Juan,Li, Hong-Xi,Young, David J.,Li, Hai-Yan,Lang, Jian-Ping
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supporting information
p. 3567 - 3574
(2019/04/14)
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- Hydroxyl- and Halogen-containing Chalcones for the Inhibition of LPS-stimulated ROS Production in RAW 264.7 Macrophages: Design, Synthesis and Structure–Activity Relationship Study
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Oxidative stress due to overproduction of reactive oxygen species (ROS) plays a major role in inflammation, cancer, and neurodegenerative disorders. In this study, 60 chalcone derivatives with fluorine (F), trifluoromethyl (CF3), trifluoromethoxy (OCF3), chlorine (Cl), and bromine (Br) in ring A and with or without hydroxy (OH) in ring B were designed, synthesized, and screened for inhibitory activity against lipopolysaccharide (LPS)-stimulated ROS production in RAW 264.7 macrophages. Structure–activity relationship study revealed the importance of a hydroxyl moiety in ring B for enhancing inhibitory activity of ROS production. Furthermore, a hydroxyl group at the ortho-position is more essential for inhibition of ROS production followed by meta- and para-positions. Among all, compound 27 that contains para-chlorine moiety in ring A and ortho-hydroxy in ring B displayed the strongest inhibitory activity (IC50 = 3.42 μM) against LPS-stimulated ROS production in RAW264.7 macrophages.
- Shrestha, Aarajana,Shrestha, Aastha,Park, Pil-Hoon,Lee, Eung-Seok
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p. 729 - 734
(2019/07/19)
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- Electrochemical 1,4-reduction of α,β-unsaturated ketones with methanol and ammonium chloride as hydrogen sources
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A sustainable, chemoselective 1,4-reduction of α,β-unsaturated ketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.
- Huang, Binbin,Li, Yanan,Yang, Chao,Xia, Wujiong
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supporting information
p. 6731 - 6734
(2019/06/17)
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- Chiral Hydroxytetraphenylene-Catalyzed Asymmetric Conjugate Addition of Boronic Acids to Enones
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(S)-2,15-Br2-DHTP-catalyzed asymmetric conjugate addition of boronic acids to β-trifluoromethyl α,β-unsaturated ketones and enones was studied. The reaction afforded the corresponding Michael addition products in moderate to high yields with excellent enantioselectivities (up to 99:1 er). This catalytic system features mild reaction conditions, high efficiency, and tolerance to heteroarylboronic acids.
- Chai, Guo-Li,Sun, A-Qiang,Zhai, Dong,Wang, Juan,Deng, Wei-Qiao,Wong, Henry N.C.,Chang, Junbiao
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supporting information
p. 5040 - 5045
(2019/07/03)
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- Enantioselective Copper-Catalyzed 1,5-Cyanotrifluoromethylation of Vinylcyclopropanes
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A copper-catalyzed enantioselective 1,5-cyanotrifluoromethylation of vinylcyclopropanes has been developed using a radical relay strategy. This asymmetric reaction has demonstrated high enantioselective control, broad substrate scope, and mild conditions. Initiated by the in situ generated CF3 radical from Togni's reagent, this method offers a new solution for remote enantioselective bifunctionalization of alkenes and thus provides a straightforward way for the synthesis of chiral CF3-containing internal alkenylnitriles.
- Zhang, Zi-Qi,Meng, Xiang-Yu,Sheng, Jie,Lan, Quan,Wang, Xi-Sheng
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supporting information
p. 8256 - 8260
(2019/10/16)
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- Synthesis and bioevaluation of thienopyrimidines bearing a pyrazoline unit as selective PI3Kα inhibitors
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A series of thienopyrimidines containing a pyrazoline unit (4a-d, 7a-d and 13a-l) were designed and synthesized. The target compounds were evaluated for antiproliferative activity against A549, HepG2 and MCF-7 cancer cell lines. Among the twenty target compounds, most of them exhibited excellent antiproliferative activity against one or several cancer cell lines. Compound 13f showed the best activity against A549, MCF-7 and HepG2 cancer cell lines, with IC50 values of 2.84 ± 0.09 μM, 2.88 ± 0.43 μM and 2.08 ± 0.36 μM, respectively. Four selected compounds (13c, 13f, 13g and 13h) were further evaluated for their inhibitory activity against the PI3Kα/mTOR protein kinase. Moreover, time-dependent and dose-dependent experiments, AO fluorescence staining, Annexin V-FITC/PI staining and docking studies were carried out in this study. The results indicated that compound 13f may be a potential selective PI3Kα inhibitor.
- Lai, Luogen,Wang, Qinqin,Zhang, Binliang,Xiao, Zhen,Yang, Zunhua,Yang, Qi,Luo, Zixin,Zhu, Wufu,Xu, Shan
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p. 29579 - 29589
(2019/10/01)
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- Pyrazolopyrimidine compound and application thereof as well as luminescent device
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The invention provides a pyrazolopyrimidine compound; the structural formula of the pyrazolopyrimidine compound is shown in the description. The pyrazolopyrimidine compound has better thermal stability, high luminous efficiency and high luminescence purit
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Paragraph 0051; 0053-0055; 0104; 0106; 0107-0108
(2018/10/04)
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- Synthesis of α, β - unsaturated ketone method
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A synthetic method for [alpha],[beta]-unsaturated ketone is a method which catalyzes a primary alconol and a secondary alcohol to oxidize and couple by a supported catalyst. The method includes the steps of adding the primary alconol, the secondary alcohol, an alkali and the catalyst into the mixed solvent mixing water and tert-butyl alcohol; stirring at 0-100 DEG C for 0.5-36 hours under the existence of an oxidizing agent. The yield of [alpha],[beta]-unsaturated ketone can reach 99% in the oxidation coupling reaction system. The synthetic method is environment friendly and has high atom economy and reaction efficiency. Moreover, the synthetic method uses non-noble metal catalyst, so that the production cost is greatly reduced.
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Paragraph 0026
(2019/01/05)
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- Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
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A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
- Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
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supporting information
p. 6659 - 6662
(2018/09/29)
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- A pyrimidine derivatives and application thereof (by machine translation)
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The invention discloses a pyrimidine derivative and its application, the pyrimidine derivatives having the following -like type (I) indicated by the structure; wherein said R1 , R2 , R3 Are selected from the carbon atom number is 1 - 60 alkyl, substituted and non-substituted aromatic heterocyclic radical, and substituted and non-substituted aromatic ring in base of any one group. The invention through the pyrimidine derivatives key chemical structure and the like is improved, and the pyrimidine derivatives as material is applied to the electro-luminescent layer in the organic electroluminescent device, compared with the prior art can effectively solve the organic electroluminescent device in blue light material of poor stability, low efficiency and the like. (by machine translation)
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Paragraph 0138; 0140; 0141; 0142
(2018/07/30)
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- Chalcone and cinnamate synthesis via one-pot enol silane formation-Mukaiyama aldol reactions of ketones and acetate esters
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Aryl alkyl ketones, acetate esters, and acetamides undergo facile one-pot enol silane formation, Mukaiyama aldol addition, and dehydrosilyloxylation in the presence of an amine base and excess trimethylsilyl trifluoromethanesulfonate. The chalcone and cinnamate products are generally recovered in high yield. The relative stoichiometry of the trimethylsilyl trifluoromethanesulfonate and amine base reagents determines whether the reaction yields the β-silyloxy carbonyl product or the α,β-unsaturated carbonyl.
- Downey, C. Wade,Glist, Hadleigh M.,Takashima, Anna,Bottum, Samuel R.,Dixon, Grant J.
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supporting information
p. 3080 - 3083
(2018/07/06)
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- Compounds for organic electroluminescent devices
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The present invention relates to boron compounds for use in electronic devices, especially organic electroluminescent devices, and to a process for preparing these compounds and to electronic devices, especially organic electroluminescent devices, comprising these compounds.
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Page/Page column 40
(2018/08/12)
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- Three-Component Synthesis of a Library of m-Terphenyl Derivatives with Embedded β-Aminoester Moieties
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The three-component reaction between alkyl- or arylamines, β-ketoesters and chalcones in refluxing ethanol containing a catalytic amount of Ce(IV) ammonium nitrate allowed the construction of a large library of highly substituted dihydro-m-terphenyl derivatives containing β-alkylamino- or β-arylamino ester moieties. This process generates three new bonds and one ring and proceeds in high atom economy, having two molecules of water as the only side product. Another domino process, in which the original MCR was telescoped with a subsequent aza Michael/retro-aza Michael sequence, allowed the one-pot preparation of a library of compounds with a N-unsubstituted β-aminoester fragment. Finally, to extend the structural diversity of these libraries, we also examined the aromatization of the central ring of our compounds in the presence of dichlorodicyanoquinone. This reaction sequence did not affect the integrity of a stereogenic center belonging to the amino component.
- Rocchi, Damiano,González, Juan F.,Gómez-Carpintero, Jorge,González-Ruiz, Víctor,Martín, M. Antonia,Sridharan, Vellaisamy,Menéndez, J. Carlos
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p. 722 - 731
(2018/10/20)
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- A robust multifunctional ligand-controlled palladium-catalyzed carbonylation reaction in water
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A novel, hydrophilic and recyclable methoxypolyethylene glycol (PEG)-modulated s-triazine-based multifunctional Schiff base/N,P-ligand L9 was prepared and used in Pd-catalyzed Heck-type carbonylative coupling reactions, affording diverse chalcone derivatives and 1,4-dicarbonyl esters in good yields.
- Gao, Pei-Sen,Zhang, Kan,Yang, Ming-Ming,Xu, Shan,Sun, Hua-Ming,Zhang, Jin-Lei,Gao, Zi-Wei,Zhang, Wei-Qiang,Xu, Li-Wen
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supporting information
p. 5074 - 5077
(2018/05/26)
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- Kinetic Resolution of β-Hydroxy Carbonyl Compounds via Enantioselective Dehydration Using a Cation-Binding Catalyst: Facile Access to Enantiopure Chiral Aldols
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A practical and highly enantioselective nonenzymatic kinetic resolution of racemic β-hydroxy carbonyl (aldol) compounds through enantioselective dehydration process was developed using a cation-binding Song's oligoethylene glycol (oligoEG) catalyst with p
- Paladhi, Sushovan,Hwang, In-Soo,Yoo, Eun Jeong,Ryu, Do Hyun,Song, Choong Eui
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supporting information
p. 2003 - 2006
(2018/04/16)
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