Cross Coupling
Mostrando 13-24 de 171 artigos, teses e dissertações.
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13. Palladium Nanoparticles Supported on Poly(
N -vinylpyrrolidone)-Grafted Silica as an Efficient Catalyst for Copper-Free Sonogashira and Suzuki Cross-Coupling ReactionsPalladium catalyst based on polyvinylpyrrolidone-silica hybrid support was prepared and exhibited excellent activity and stability in copper, amine and phosphine-free Sonogashira-Hagihara and Suzuki-Miyaura cross-coupling reactions. The polymeric catalyst was applied efficiently in the coupling reactions of chloro (as well as iodo) and bromoarenes. Elemen
J. Braz. Chem. Soc.. Publicado em: 2015-08
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14. EFFECTS OF SOLVENT, BASE, AND TEMPERATURE IN THE OPTIMISATION OF A NEW CATALYTIC SYSTEM FOR SONOGASHIRA CROSS-COUPLING USING NCP PINCER PALLADACYCLE
The optimisation of a new catalyst system using NCP pincer palladacycle
1 was investigated using the experimental design technique. NCP pincer palladacycle1 was previously investigated in Suzuki-Miyaura and Heck-Mizoroki cross-couplings and found to be a highly efficient catalyst precursor. In this study, the effects of the typeQuím. Nova. Publicado em: 2015-06
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15. Synthesis of Biphenyl Tyrosine Via Cross-Coupling Suzuki-Miyaura Reaction Using Aryltrifluoroborate Salts
We reported a fast and easy method for obtaining biarylic units from tyrosine derivatives via Suzuki-Miyaura cross-coupling using a variety of substituted and unsubstituted potassium aryl- and heteroaryltrifluoroborate salts. The scope of the methodology was also extended to the formation of bis-tyrosine linked dipeptide bonds, leading to biologically intere
J. Braz. Chem. Soc.. Publicado em: 2015-04
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16. Investigating cardiolocomotor synchronization during running in trained and untrained males
Introduction This study aims at investigating the coupling of the cardiac and locomotor systems during running in trained and untrained males. Methods Sixteen healthy young males subjects were submitted to an anthropometric evaluation, followed by a treadmill test at 70% to 75% of heart rate reserve. Based on the average velocity, they were divided into two
Res. Biomed. Eng.. Publicado em: 2015-04
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17. An efficient coupled polynomial interpolation scheme to eliminate material-locking in the Euler-Bernoulli piezoelectric beam finite element
The convergence characteristic of the conventional two-noded Euler-Bernoulli piezoelectric beam finite element depends on the configuration of the beam cross-section. The element shows slower convergence for the asymmetric material distribution in the beam cross-section due to 'material-locking' caused by extension-bending coupling. Hence, the use of convent
Lat. Am. j. solids struct.. Publicado em: 2015-01
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18. Recent Progress in the Use of Pd-Catalyzed C-C Cross-Coupling Reactions in the Synthesis of Pharmaceutical Compounds
A grande capacidade do paládio de formar ligações carbono-carbono entre substratos apropriadamente funcionalizados permitiu que os químicos orgânicos efetuassem transformações antes impossíveis ou alcançáveis somente através de rotas muito longas. Neste contexto, uma das mais elegantes e importantes aplicações das reações de acoplamento cruzad
J. Braz. Chem. Soc.. Publicado em: 2014-12
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19. Probe-Fed linearly-polarized electrically-equivalent microstrip antennas on FR4 substrates
This paper describes a simple but efficient procedure for designing electrically-equivalent microstrip antennas on FR4 sub-strates. Radiation patterns, reflection coefficient magnitude ( |Γ| ), mutual coupling and cross-polarization level of probe-fed linearly-polarized antennas are calculated and discussed. Experimental results of |Γ| and radiation patter
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-06
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20. Effects of eugenol on resting tension of rat atria
In cardiac and skeletal muscle, eugenol (μM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isol
Braz J Med Biol Res. Publicado em: 21/03/2014
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21. Desenvolvimento de reator tipo "dip catalyst" para filmes poliméricos contendo nanopartículas de metais de transição
This article describes the development of a new catalytic reactor designed to operate with nanoparticle-embedded polymer thin films. Stabilization of metal nanoparticles in films that serve as catalysts in organic reactions is relatively new; therefore, the development of reactors to facilitate their use is necessary. We describe in detail the preparation of
Quím. Nova. Publicado em: 2014
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22. Miniprojeto para ensino de Química Orgânica Experimental baseado no acoplamento catalítico N-C promovido por micro-ondas
This paper describes a three-week mini-project for an Experimental Organic Chemistry course. The activities include N-C cross-coupling synthesis of N-(4-methoxyphenyl) benzamide in an adapted microwave oven by a copper catalyst (CuI). Abilities and concepts normally present in practical organic chemistry courses are covered: use of balances, volumetric glass
Quím. Nova. Publicado em: 2013
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23. Síntese de 4-organocalcogenoil-1H-1,2,3-triazol: funcionalização da unidade triazólica via acoplamento de Negishi catalisado por níquel / 4-Organochalcogenoyl-1H-1,2,3-triazole synthesis: functionalization of the triazole scaffold by nickel-catalyzed Negishi cross-coupling
No presente trabalho, uma série de calcogenotriazóis (3a-o,5a-f) foi sintetizada empregando reações de cicloadição entre azidas e alquinos catalisadas por cobre (CAACu), com duas diferentes metodologias: uma aplicada aos selenetos e outra aos teluretos triazólicos. Os selenetos acetilênicos (1a,b) foram submetidos ao sistema catalítico Cu(OAc)2/asco
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/08/2012
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24. Ondas gravitacionais e o espectro de anisotropia tensorial na presença de neutrinos cosmológicos
In this work we have studied the evolution of primordial gravitational waves coupled to anisotropic stress tensor of cosmological neutrinos. As in a radiation dominated universe, in a universe dominated by radiation and matter the neutrinos can work as an effective dispersive medium for the gravitational waves, besides introduce small modifications over the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/07/2012