- A polymer supported palladium(II) β-ketoesterate complex as active and recyclable pre-catalyst for selective reduction of quinolines in water with sodium borohydride Dedicated to the memory of Professor Benedetto Corain.
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A polymer supported palladium catalyst, obtained by copolymerization of Pd(AAEMA)2 [AAEMA- = deprotonated form of 2-(acetoacetoxy) ethyl methacrylate] with ethyl methacrylate (co-monomer) and ethylene glycol dimethacrylate (cross-linker), exhibited excellent activity and selectivity for the hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines in the presence of NaBH4 as hydrogen donor in water. Both the activity and selectivity could be maintained for at least seven reaction runs. No metal leaching into solution occurred during recycles. TEM analyzes carried out on the catalyst showed that the active species were supported palladium nanoparticles having a mean size of 3 nm, which did not aggregate with the recycles.
- Dell'Anna, Maria Michela,Romanazzi, Giuseppe,Intini, Simona,Rizzuti, Antonino,Leonelli, Cristina,Piccinni, Alberto Ferruccio,Mastrorilli, Piero
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- Synthesis and biological evaluation of N9-substituted harmine derivatives as potential anticancer agents
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A series of N9-substituted harmine derivatives were synthesized and evaluated for their anticancer activity on a panel of cancer cell lines, their apoptosis induction and their cell cycle effects. The results showed that N9-substituted harmine derivatives had anticancer effects. In particular, N9-haloalkyl derivatives 9a–9c and N9-acyl harmine derivatives 11c and 11d, with IC50values less than 1?μM, were more potent than doxorubicin against A-549 and/or MCF-7 cell lines. Moreover, structure–activity relationships (SARs) indicated that introducing a haloalkyl or benzenesulfonyl group in the N9-position of harmine could significantly increase the anticancer activity. The most active compound (11d) caused cell cycle arrest in the G2/M phase, and induced cell apoptosis in a dose-dependent manner.
- Du, Hongtao,Tian, Shan,Chen, Juncheng,Gu, Hongling,Li, Na,Wang, Junru
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- Facile heterogeneous catalytic hydrogenations of C=N and C=O bonds in neat water: Anchoring of water-soluble metal complexes onto ion-exchange resins
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Rare examples are known of non-covalent immobilization of water-soluble transition metal complexes onto solid supports and their application in catalytic hydrogenations in neat water. In the present work we report on the synthesis of a novel Ir(i) complex bearing the water soluble monodentate cage phosphine PTA (PTA = 1,3,5-triaza-7-phosphaadamantane) and its immobilisation onto commercial ion-exchange resins by a straightforward heterogenization method. The materials obtained were used as catalysts for the hydrogenations of cyclic imines and α-keto esters under mild conditions using water as a green reaction medium, avoiding as much as possible the use of toxic and/or hazardous solvents.
- Barbaro, Pierluigi,Gonsalvi, Luca,Guerriero, Antonella,Liguori, Francesca
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- Highly selective hydrogenation of quinolines promoted by recyclable polymer supported palladium nanoparticles under mild conditions in aqueous medium
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Polymer supported palladium catalyst, obtained by copolymerization of Pd(AAEMA)2 [AAEMA- = deprotonated form of 2-(acetoacetoxy)ethyl methacrylate] with ethyl methacrylate (co-monomer) and ethylene glycol dimethacrylate (cross-linker), exhibited excellent activity and selectivity for the hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines under mild temperature (80 °C) and H2 pressure (10 bar) in aqueous medium. Both the activity and selectivity could be maintained for at least nine reaction runs. No metal leaching into solution occurred during application. TEM analyses carried out on the catalyst showed that the active species were supported palladium nanoparticles having a mean size of 4 nm, which did not aggregate with the recycles.
- Dell'Anna, Maria Michela,Capodiferro, Vito Filippo,Mali, Matilda,Manno, Daniela,Cotugno, Pietro,Monopoli, Antonio,Mastrorilli, Piero
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- Dehydrogenation of N-Heterocycles by Superoxide Ion Generated through Single-Electron Transfer
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Nitrogen-containing heteroarene motifs are found in numerous pharmaceuticals, natural products, and synthetic materials. Although several elegant methods for synthesis of these compounds through dehydrogenation of the corresponding saturated heterocycles have been reported, some of the methods are hampered by long reaction times, harsh conditions, and the need for catalysts that are not readily available. This work reports a novel method for dehydrogenation of N-heterocycles. Specifically, O2.? generated in situ acts as the oxidant for N-heterocycle substrates that are susceptible to oxidation through a hydrogen atom transfer mechanism. This method provides a general, green route to N-heteroarenes.
- Huang, Yuan-Qiong,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
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supporting information
p. 2065 - 2069
(2018/01/27)
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- Recyclable cobalt(0) nanoparticle catalysts for hydrogenations
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The search for new hydrogenation catalysts that replace noble metals is largely driven by sustainability concerns and the distinct mechanistic features of 3d transition metals. Several combinations of cobalt precursors and specific ligands in the presence of reductants or under high-thermal conditions were reported to provide active hydrogenation catalysts. This study reports a new method of preparation of small, monodisperse Co(0) nanoparticles (3-4 nm) from the reduction of commercial CoCl2 in the absence of ligands or surfactants. High catalytic activity was observed in hydrogenations of alkenes, alkynes, imines, and heteroarenes (2-20 bar H2). The magnetic properties enabled catalyst separation and multiple recyclings.
- Büschelberger, Philipp,Reyes-Rodriguez, Efrain,Sch?ttle, Christian,Treptow, Jens,Feldmann, Claus,Jacobi Von Wangelin, Axel,Wolf, Robert
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p. 2648 - 2653
(2018/05/30)
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- 2 - substituted β - carbolines compound and its used for preparation for preventing or treating tumor drug application
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The invention provides 2-substituted-beta-carboline compounds and application thereof in preparing drugs for preventing or treating tumors. The structural general formula of the compounds is disclosed as Formula I. The compounds have high inhibiting actions on growth of tumor cells, and have approximate activity to the positive control paclitaxel. Part of the compounds have obviously better antitumor activity than the paclitaxel; the IC50 value is less than 1 mu M; and thus, the compounds can become efficient drugs for treating tumors.
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Paragraph 0034-0036
(2017/04/29)
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- ?-CARBOLINE, DIHYDRO-?-CARBOLINE AND TETRAHYDRO-?-CARBOLINE ALKALOID DERIVATIVES AND PREPARATION METHODS SAME AND USE IN ASPECTS OF PREVENTING AND TREATING PLANT VIRUSES, FUNGICIDES AND INSECTICIDES
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The present invention relates to β-carboline, dihydro-β-carboline and tetrahydro-β-carboline alkaloid derivatives (I) and a method for preparing same and the use in the aspects of preventing and treating plant viruses, fungicides and insecticides. For the meaning of each group in formula (I) see the description. The β-carboline, dihydro-β-carboline and tetrahydro-β-carboline alkaloid derivatives of the present invention show a particularly ourstanding anti-plant virus activity, and also have fungicidal and insecticidal activities.
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- Synthesis and antiviral and fungicidal activity evaluation of β-carboline, dihydro-β-carboline, tetrahydro-β-carboline alkaloids, and their derivatives
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Six known β-carboline, dihydro-β-carboline, and tetrahydro-β-carboline alkaloids and a series of their derivatives were designed, synthesized, and evaluated for their anti-tobacco mosaic virus (TMV) and fungicidal activities for the first time. All of the alkaloids and some of their derivatives (compounds 3, 4, 14, and 19) exhibited higher anti-TMV activity than the commercial antiviral agent Ribavirin both in vitro and in vivo. Especially, the inactivation, curative, and protection activities of alkaloids Harmalan (62.3, 55.1, and 60.3% at 500 μg/mL) and tetrahydroharmane (64.2, 57.2, and 59.5% at 500 μg/mL) in vivo were much higher than those of Ribavirin (37.4, 36.2, and 38.5% at 500 μg/mL). A new derivative, 14, with optimized physicochemical properties, obviously exhibited higher activities in vivo (50.4, 43.9, and 47.9% at 500 μg/mL) than Ribavirin and other derivatives; therefore, 14 can be used as a new lead structure for the development of anti-TMV drugs. Moreover, most of these compounds exhibited good fungicidal activity against 14 kinds of fungi, especially compounds 4, 7, and 11.
- Song, Hongjian,Liu, Yongxian,Liu, Yuxiu,Wang, Lizhong,Wang, Qingmin
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p. 1010 - 1018
(2014/03/21)
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- Synthesis and antiviral and fungicidal activity evaluation of β-carboline, dihydro-β-carboline, tetrahydro-β-carboline alkaloids, and their derivatives
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Six known β-carboline, dihydro-β-carboline, and tetrahydro-β-carboline alkaloids and a series of their derivatives were designed, synthesized, and evaluated for their anti-tobacco mosaic virus (TMV) and fungicidal activities for the first time. All of the alkaloids and some of their derivatives (compounds 3, 4, 14, and 19) exhibited higher anti-TMV activity than the commercial antiviral agent Ribavirin both in vitro and in vivo. Especially, the inactivation, curative, and protection activities of alkaloids Harmalan (62.3, 55.1, and 60.3% at 500 μg/mL) and tetrahydroharmane (64.2, 57.2, and 59.5% at 500 μg/mL) in vivo were much higher than those of Ribavirin (37.4, 36.2, and 38.5% at 500 μg/mL). A new derivative, 14, with optimized physicochemical properties, obviously exhibited higher activities in vivo (50.4, 43.9, and 47.9% at 500 μg/mL) than Ribavirin and other derivatives; therefore, 14 can be used as a new lead structure for the development of anti-TMV drugs. Moreover, most of these compounds exhibited good fungicidal activity against 14 kinds of fungi, especially compounds 4, 7, and 11.
- Song, Hongjian,Liu, Yongxian,Liu, Yuxiu,Wang, Lizhong,Wang, Qingmin
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p. 1010 - 1018
(2015/04/22)
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- Acceptorless dehydrogenation of nitrogen heterocycles with a versatile iridium catalyst
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Gas up: A cyclometalated iridium complex is found to catalyze the dehydrogenation of various benzofused N-heterocycles, thus releasing H 2. Driven by as low as 0.1 mol % catalyst, the reaction affords quinolines, indoles, quinoxalines, isoquinolines, and β-carbolines in high yields. Copyright
- Wu, Jianjun,Talwar, Dinesh,Johnston, Steven,Yan, Ming,Xiao, Jianliang
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supporting information
p. 6983 - 6987
(2013/07/26)
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- Engineering an enantioselective amine oxidase for the synthesis of pharmaceutical building blocks and alkaloid natural products
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The development of cost-effective and sustainable catalytic methods for the production of enantiomerically pure chiral amines is a key challenge facing the pharmaceutical and fine chemical industries. This challenge is highlighted by the estimate that 40-45% of drug candidates contain a chiral amine, fueling a demand for broadly applicable synthetic methods that deliver target structures in high yield and enantiomeric excess. Herein we describe the development and application of a "toolbox" of monoamine oxidase variants from Aspergillus niger (MAO-N) which display remarkable substrate scope and tolerance for sterically demanding motifs, including a new variant, which exhibits high activity and enantioselectivity toward substrates containing the aminodiphenylmethane (benzhydrylamine) template. By combining rational structure-guided engineering with high-throughput screening, it has been possible to expand the substrate scope of MAO-N to accommodate amine substrates containing bulky aryl substituents. These engineered MAO-N biocatalysts have been applied in deracemization reactions for the efficient asymmetric synthesis of the generic active pharmaceutical ingredients Solifenacin and Levocetirizine as well as the natural products (R)-coniine, (R)-eleagnine, and (R)-leptaflorine. We also report a novel MAO-N mediated asymmetric oxidative Pictet-Spengler approach to the synthesis of (R)-harmicine.
- Ghislieri, Diego,Green, Anthony P.,Pontini, Marta,Willies, Simon C.,Rowles, Ian,Frank, Annika,Grogan, Gideon,Turner, Nicholas J.
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supporting information
p. 10863 - 10869
(2013/08/23)
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- Reaction of Harmidine/Harmaline with BrCN - a Facile Mono- and Di-Bromination at α-Carbon of the Imine Tautomer
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Reaction of harmidine/harmaline with BrCN has afforded mono- and di-bromo derivatives I and II respectively indicating the substitution of bromine at the α-carbon of imine through its enamine tautomer. - Key words: von Braun Cyanogen Bromide, Bromination
- Siddiqui, Salimuzzaman,Siddiqui, Bina S.,Begum, Sabira
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p. 1747 - 1748
(2007/10/02)
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