- Sol-gel synthesis of ceria-zirconia-based high-entropy oxides as high-promotion catalysts for the synthesis of 1,2-diketones from aldehyde
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Efficient Lewis-acid-catalyzed direct conversion of aldehydes to 1,2-diketones in the liquid phase was enabled by using newly designed and developed ceria–zirconia-based high-entropy oxides (HEOs) as the actual catalysts. The synergistic effect of various cations incorporated in the same oxide structure (framework) was partially responsible for the efficiency of multicationic materials compared to the corresponding single-cation oxide forms. Furthermore, a clear, linear relationship between the Lewis acidity and the catalytic activity of the HEOs was observed. Due to the developed strategy, exclusively diketone-selective, recyclable, versatile heterogeneous catalytic transformation of aldehydes can be realized under mild reaction conditions.
- Dinjar, Kristijan,Djerdj, Igor,Koj?inovi?, Jelena,Kukovecz, ákos,Markovi?, Berislav,Mileti?, Aleksandar,Nagy, Sándor Balázs,Sapi, Andras,Stenzel, David,Széchenyi, Aleksandar,Szenti, Imre,Tang, Yushu,Tatar, Dalibor,Varga, Gábor,Ziegenheim, Szilveszter
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- Synthesis and evaluation of quinoxaline derivatives as potential influenza NS1A protein inhibitors
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A library of quinoxaline derivatives were prepared to target non-structural protein 1 of influenza A (NS1A) as a means to develop anti-influenza drug leads. An in vitro fluorescence polarization assay demonstrated that these compounds disrupted the dsRNA-NS1A interaction to varying extents. Changes of substituent at positions 2, 3 and 6 on the quinoxaline ring led to variance in responses. The most active compounds (35 and 44) had IC50 values in the range of low micromolar concentration without exhibiting significant dsRNA intercalation. Compound 44 was able to inhibit influenza A/Udorn/72 virus growth.
- You, Lei,Cho, Eun Jeong,Leavitt, John,Ma, Li-Chung,Montelione, Gaetano T.,Anslyn, Eric V.,Krug, Robert M.,Ellington, Andrew,Robertus, Jon D.
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p. 3007 - 3011
(2011/06/24)
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- COMPOUNDS, COMPOSITIONS AND METHODS FOR THE TREATMENT OF AMYLOID DISEASES AND SYNUCLEINOPATHIES SUCH AS ALZHEIMER'S DISEASE, TYPE 2 DIABETES, AND PARKINSON'S DISEASE
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Bis- and tris-dihydroxyaryl compounds and their methylenedioxy analogs and pharmaceutically acceptable esters, their synthesis, pharmaceutical compositions containing them, and their use in the treatment of amyloid diseases, especially A? amyloidosis, such as observed in Alzheimer's disease, IAPP amyloidosis, such as observed in type 2 diabetes, and synucleinophathies, such as observed in Parkinson's disease, and the manufacture of medicaments for such treatment.
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- Photogeneration of amines from α-keto carbamates: Design and preparation of photoactive compounds
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The design and synthesis of substituted desyl (2-oxo-1,2-diphenylethyl) groups has been investigated to create new photolabile protecting groups. The photoreactivity of these chromophores stems from the diverse photochemistry of the desyl group. Several chromophore designs have been explored in which the substitution pattern of the parent desyl chromophore was varied systematically. The required benzoin chromophores are prepared by a variety of synthetic routes, depending on the structure of the benzoin chromophore desired. Symmetrical benzoins are readily available via the benzoin condensation. Unsymmetrical benzoins including 2,2-disubstituted α-hydroxy ketones are generally prepared via trimethylsilyl (TMS) masked cyanohydrins. On reaction with a Grignard reagent, the TMS masked cyanohydrin functions as an α-hydroxycarbonyl equivalent to form α-hydroxy ketones. Alternatively, lithiation of a TMS masked cyanohydrin generates a benzoyl anion equivalent which reacts with aldehydes and ketones to generate substituted benzoins. These desyl chromophores have significant potential as new photolabile protecting moieties for a variety of functional groups and are used to mask primary and secondary amines as photosensitive α-keto carbamates. The substituted benzoin carbamates are readily prepared from the appropriate benzoin by reaction with isocyanates or by activation as a mixed carbonate followed by reaction with the free amine. These α-keto carbamates are interesting for two main reasons. First, the facile synthesis of these materials indicates the ease of introduction of the desyl based photolabile group. Second, these α-keto carbamates may be used for rapid evaluation of novel photoactive desyl based chromophores.
- Cameron, James F.,Willson, C. Grant,Frechet, Jean M. J.
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p. 2429 - 2442
(2007/10/03)
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- Oxidation by DMSO. II. An efficient synthesis of α,β-diketones from α,β-dibromides
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α,β-Dibromides refluxed in DMSO are oxidised into α,β-diketones. The reaction takes place rapidly under microwave irradiation.
- Villemin,Hammadi
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p. 3145 - 3148
(2007/10/02)
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- CYANOHYDRINS AS SUBSTRATES IN BENZOIN CONDENSATION. REGIOCONTROLLED MIXED BENZOIN CONDENSATION
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O-Benzoylated cyanohydrins of aromatic aldehydes have been used as one of the substrates in the benzoin condensation.They were treated with aromatic aldehydes under phase-transfer conditions to result in benzoin benzoates.By this method aldehydes which fail to undergo condensation using traditional conditions could be converted into benzoins.By the Umpolung of reactivity of the pertinent aldehyde it was possible to prepare both isomeric unsymmetrical benzoins, including the thermodynamically less stable ones.
- Rozwadowska, Maria D.
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p. 3135 - 3140
(2007/10/02)
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- An Unusual Reaction of a Phosphorane with Benzoins: Formation of 1,2-Dicarbonyl and 1,4-Dicarbonyl Compounds
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Benzoins (1a-e) on reaction with carbethoxymethylenetriphenylphosphorane (2) furnish hydroxy esters (3a-e) and butenolides (4a and 4e) along with the unusual products, benzils (5a-e) and ketoesters (6a-e) as major product.
- Ranade, A. C.,Mali, R. S.,Kurnawal, V. M.
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p. 514 - 517
(2007/10/02)
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- BIS(2,2'-BIPYRIDYL)COPPER(II) PERMANGANATE (BBCP): A MILD AND VERSATILE OXIDANT IN ORGANIC SYNTHESIS
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The preparation of bis(2,2'-bipyridyl)copper(II) permanganate (BBCP) is described.The reagent converts alcohols to the corresponding carbonyl compounds, α-hydroxy ketones to diketones, hydroquinone to p-benzoquinone, and compounds with benzylic double bonds to benzaldehyde in high yield.Benzophenone oxime, acetophenone oxime and various benzaldoximes are converted to the corresponding carbonyl compounds, aromatic amines to azo compounds, and benzylamine to benzaldehyde, usually in high yields, under mild condition.
- Firouzabadi, H.,Sardarian, A. R.,Naderi, M.,Vessal, B.
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p. 5001 - 5004
(2007/10/02)
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- CERIUM(IV) AMMONIUM NITRATE-CHARCOAL SYSTEM. AN EFFECTIVE CATALYST FOR THE AIR OXIDATION OF BENZYL ALCOHOLS AND ACYLOINS
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Cerium(IV) ammonium nitrate (CAN) adsorbed on activated charcoal has been found to be an effective catalyst for the air oxidation of benzyl alcohols and acyloins to the corresponding carbonyl compounds.
- Hatanaka, Yasuo,Imamoto, Tsuneo,Yokoyama, Masataka
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p. 2399 - 2400
(2007/10/02)
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