Nuclear Reactions
Mostrando 13-24 de 382 artigos, teses e dissertações.
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13. Palladium Nanoparticles Supported on β-cyclodextrin Functionalised Poly(amido amine)s and their Application in Suzuki-Miyaura Cross-Coupling Reactions
Herein, the synthesis, characterization and catalytic application of an organic-inorganic, palladium (Pd)-containing hybrid material, poly(amidoamine)-cyclodextrin (Pd@PAAs-CD), is reported as an efficient catalyst for Suzuki-Miyaura coupling reactions. The structure of Pd@PAAs-CD was confirmed by Fourier transform infrared spectroscopy (FTIR), transmission
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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14. Synthesis and characterization of isoprene oligomers to compare different production chemical processes
Abstract Three methods to obtain isoprene oligomers were evaluated: chemical degradation of non-vulcanized coagulated natural rubber; chemical degradation of natural rubber latex; and oligomerization of the isoprene monomer. The products were characterized by infrared spectrometry (FTIR), nuclear magnetic resonance (NMR) and size-exclusion chromatography (S
Polímeros. Publicado em: 18/03/2019
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15. Synthesis of Spiro-Pyrrolidinyloxindoles by Oxidative Rearrangement of N-Acyltetrahydro-β-carbolines Using an Oxone/Aqueous Acetone Mixture
Spiro-pyrrolidinyl-2-oxindoles were prepared by the oxidative rearrangement of Na-acetyl-1,2,3,4-tetrahydro-β-carbolines (THBC) using dimethyldioxirane generated in situ. The Na-acetyl THBC substrates were obtained by Pictet-Spengler and acyl-Pictet-Spengler reactions of L-tryptophan methyl ester, followed by Na-acetylation. The stereoselectivity of the oxi
J. Braz. Chem. Soc.. Publicado em: 2019-01
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16. Brazil, the United States and the Tehran Declaration
Abstract Brazil has claimed the status of a key player within the international arena for the past decade, particularly during the two administrations of Lula da Silva (2003–2010). The Brazilian foreign policy team acted in relation to issues such as the Palestinian-Israeli Affairs and the Iranian Nuclear Program imbroglio with the international community
Rev. bras. polít. int.. Publicado em: 23/11/2018
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17. Synthesis and Application of Bimetallic Zinc(II) Phenoxy-Imine Complexes as Initiators for Production of Lactide Polymers
This article reports the synthesis of two bimetallic zinc(II) complexes containing phenoxy-imine ligands and their application as initiators of ring opening polymerization (ROP) of L-lactide (LA). The phenoxy-imine ligands were obtained from salicylaldehyde derivatives and 2,3,5,6-tetramethylphenylenediamine, yielding two bidentate regions per ligand. The re
J. Braz. Chem. Soc.. Publicado em: 2018-02
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18. Synthetic Niobium Oxyhydroxide as a Bifunctional Catalyst for Production of Ethers and Allyl Alcohol from Waste Glycerol
A synthetic niobia was modified by treatment with hydrogen peroxide to be used as a catalyst for converting glycerol into petrochemical compounds. The catalytic properties of niobium oxyhydroxide were obtained by generating acidic and oxygenated groups (peroxo groups) on the solid surface. Compounds like ethers and allyl alcohol were obtained. A very active
J. Braz. Chem. Soc.. Publicado em: 2017-11
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19. Synthesis and Evaluation of Cytotoxic Effects of Amino-ester Derivatives of Natural α,β-Amyrin Mixture
Natural α,β-amyrins were isolated from endemic Brazilian Esenbeckia grandiflora Mart., and eight synthetic derivatives were obtained by esterification reactions with bromo acetate, followed by amine treatment. The structures of the all compounds were confirmed by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and high-resolu
J. Braz. Chem. Soc.. Publicado em: 2017-11
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20. Microwave Assisted Synthesis of Novel Six-Membered 4-C, 4-O and 4-S Lactams Derivatives: Characterization and in vitro Biological Evaluation of Cytotoxicity and Anticoagulant Activity
A series of six-membered lactam derivatives containing C, O and S atoms in position 4 were synthesized using microwave methodology through coupling reactions. The novel compounds were synthesized following two step reaction to yield fifteen derivatives. The final derivative N-(4-(3-oxotiomorpholin)phenyl) hexanamide was selectively toxic to the HCT-116 cell
J. Braz. Chem. Soc.. Publicado em: 2017-02
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21. A New Post-Metallocene-Ti Catalyst with Maltolate Bidentade Ligand: an Investigation in Heterogeneous Polymerization Reactions in Different Mesoporous Supports
A new titanium catalyst easily synthesized from ethylmaltol bidentate chelator ligand was studied in homogeneous and heterogeneous ethylene polymerization. The dichlorobis(3-hydroxy-2-ethyl-4-pyrone)titanium(IV) complex was characterized by 1H and 13C NMR (nuclear magnetic resonance), UV-Vis and elemental analysis. Theoretical study by density functional the
J. Braz. Chem. Soc.. Publicado em: 2016-11
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22. Expression of CD90 and P75NTR stem cell markers in ameloblastomas: a possible role in their biological behavior
Abstract Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evalu
Braz. oral res.. Publicado em: 10/10/2016
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23. Simplification of Lipase Design in the Enzymatic Kinetic Resolution of Amines by Saturation Transfer Difference NMR
In this work, we demonstrate a nuclear magnetic resonance (NMR) method for racemic amide and lipase interaction as a first-pass design method in the enzymatic kinetic resolution of amines. As a novel adaptation of commonly used protein-ligand screening NMR methodologies, this approach relies upon a lipase-amide interaction wherein the time-consuming is reduc
J. Braz. Chem. Soc.. Publicado em: 2016-10
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24. Derivatives of Cardanol through the Ene Reaction with Diethyl Azodicarboxylate
Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was facile and required only the application of heat without a cat
J. Braz. Chem. Soc.. Publicado em: 2016-06