Ring-opening
A model compound for pyridinechalcone-based multistate systems. Ring opening-closure as the slowest kinetic step of the multistate
... UV-vis absorption including stopped-flow for the faster kinetic steps. In the parent 4- pyridinechalcone compound, protonation of the pyridine nitrogen for pH<4 prevents formation of the flavylium cation. In compound ...
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REPOSITORIO INSTITUCIONAL DA UFOP: Functional polylactide via ring-opening copolymerisation with allyl, benzyl and propargyl glycidyl ethers.
... Within the library of compounds susceptible to undergo ring-opening (co)polymerisation, glycidyl ethers may be obtained from commercial sources with a variety of functional groups. In addition, conjugation ...
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J. Braz. Chem. Soc. vol.24 número11
... Also, the chemical reactivity of carboxamide 1 was studied towards a variety of carbon nucleophiles. Thus, the treatment of carboxamide 1 with malononitrile in ethanol containing few drops of piperidine afforded the ...
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Anhydrous ZnCl2: A Highly Efficient Reagent for Facile and Regioselective Conversion of Epoxides to β-Chlorohydrins
... reaction conditions. All epoxides were easily and efficiently converted to the corresponding β- chlorohydrins in excellent yields and regioselectivity. The reactions were completed within 10-50 min without formation of ...
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Rev. Bras. Cienc. Farm. vol.40 número3
... SHIGEMASA, Y.; USUI, H.,; MORIMOTO, M.; SAIMOTO, H.; OKAMOTO, Y.;MINAMI, S.; SASHIWA, H. Chemical modification of chitin and chitosan: preparation of partially deacetylated chitin derivatives via a ...
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J. Braz. Chem. Soc. vol.28 número7
... Azlactones are useful building blocks in the synthesis of functional amino acid derivatives, heterocycles and bioactive molecules. In this work, a protocol for the organocatalytic functionalization of dipeptides has been ...
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Influência dos ligantes ancilares na reatividade de complexos de rutênio como iniciadores...
... ν SZYMAŃSKA -BUZAR, T., Ring-opening metathesis polymerization of norbornene and norbornadiene by tungsten(II) and molybdenum(II) complexes, Journal of Molecular Catalysis A: Chemical,[r] ...
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J. Braz. Chem. Soc. vol.16 número3B
... Ring-opening reaction of epoxides with nucleophiles has been widely used to the preparation of some starting materials that are very important in organic synthesis. Among them thiolyzation of epoxides has ...
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Photochemical synthesis and functional transformations of bicyclic vinyl aziridines
... nucleophilic ring-opening reaction of aziridines in aqueous media was here ...nucleophilic ring-opening reaction in water under physiological conditions was investigated and a range of ...
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Efeito do sinergismo eletrônico na atividade catalítica de complexos [RuCl2(PPh3)2(amina)]...
... A pesquisa tem se voltado para a síntese e aplicação de catalisadores em metátese do tipo ROMP e ROMCP ( Ring Opening Metathesis Copolymerization ), em meio aquoso ou orgâni[r] ...
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Síntese de amino-complexos de rutênio e suas aplicações como catalisadores em reações...
... Este trabalho está organizado em capítulos correspondentes aos manuscritos publicados (APÊNDICE A), bem como aos aceitos (APÊNDICE B) a revistas científicas. Capítulo 1 abrange uma introdução geral sobre metátese de ...
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J. Braz. Chem. Soc. vol.22 número6
... with 1,4-binucleophiles proceeds via γ-pyrone ring opening followed by an intramolecular condensation reaction to effect cyclization leading to seven membered ring systems. Moreover, the reaction of ...
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J. Braz. Chem. Soc. vol.25 número1
... phenyl ring attached to 1,3,4-oxadiazole ring were synthesized and well ...phenyl ring attached to 1,3,4-oxadiazole framework causes marked increase in both antibacterial as well as antifungal ...
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J. Braz. Chem. Soc. vol.12 número5
... this approach, in which the rigid cycloadduct can be transformed with complete stereochemical control before the ring rearrangement occurs, and the new conformationally flexible medium ring is liberated ...
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The oolitization rate determination of bentonite moulding mixtures
... influence on the castings surface quality and that even in case of the foundry plant B where the sample was taken from the mould’s front (Tab. 4). The oolitization rate was only (0.76-3.24%) in this case which is deep ...
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Synthesis and Alcoholysis of <i>α</i>-Alkylated Cyclopentane and Cyclohexane Fused Succinic Racemic Anhydrides in the Presence of Chiral Bases
... Two series of cyclic anhydrides were prepared: first one possessing cyclopentane ring fused to succinic anhydride and the second one with fused cyclohexane ring. Anhy- drides 11–14 were prepared starting ...
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O americanismo de Aureliano Cândido Tavares Bastos
... O vale do Amazonas expanded the examination initiated in Cartas do Solitário. Once again Tavares Bastos defends the approach with the United States. He also denies that the United States was acting im- perialistically ...
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A three-dimensional ring-array concentrator solar furnace
... parabolic ring array concentrators (RAC) are, however, much less ...the ring array concentrator research similar to the Pyreheliophoro, a type of solar concentrator from 19 th centrury ...
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Numerical Determination of Crack Opening and Closure Stress Intensity Factors
... crack opening and negative to characterize the crack ...crack opening or closure: – the first contact of the crack flank, which corresponds to the contact of the first node behind the current crack ...the ...
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On the Codes over a Semilocal Finite Ring
... In this paper, we have introduced skew cyclic, skew quasi- cyclic, skew constacyclic and skew quasi-constacyclic codes over the finite ring R. By using the Gray map, we have studied the Gray images of cyclic, ...
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