نتایج جستجو برای: palladium

تعداد نتایج: 12345  

2012
Kalicharan Chattopadhyay Erik Fenster Alexander J Grenning Jon A Tunge

The palladium-catalyzed nucleophilic substitution of (coumarinyl)methyl acetates is described. The reaction proceeds though a palladium π-benzyl-like complex and allows for many different types of C-, N-, and S-nucleophiles to be regioselectively added to the biologically active coumarin motif. This new method was utilized to prepare a 128-membered library of aminated coumarins for biological s...

Journal: :Chemical communications 2012
Guanyinsheng Qiu Gang Liu Shouzhi Pu Jie Wu

A novel and efficient route for the preparation of quinazolin-4(3H)-imines via a palladium-catalyzed three-component reaction of carbodiimide, isocyanide, and nucleophile is described. The palladium-catalyzed isocyanide insertion is believed to be the key step during the reaction process.

Journal: :Angewandte Chemie 2015
Chuanhu Lei Xiaojia Jin Jianrong Steve Zhou

Three-component couplings were achieved from common aryl halides, alkyl halides, and heteroarenes under palladium and norbornene co-catalysis. The reaction forges hindered aryl-heteroaryl bonds and introduces ortho-alkyl groups to aryl rings. Various heterocycles such as oxazoles, thiazoles and thiophenes underwent efficient coupling. The heteroarenes were deprotonated in situ by bases without ...

Journal: :Molecules 2013
Jana Doháňošová Tibor Gracza

The palladium (II)-catalysed reactions of alkenols and aminoalkenols such as oxycarbonylations or bicyclisations are powerful methods for the construction of oxygen and nitrogen-containing heterocyclic compounds. This review highlights recent progress in the development of the asymmetric palladium(II)-catalysed Wacker-type cyclisations of unsaturated polyols and aminoalcohols. The scope, limita...

Journal: :Organic & biomolecular chemistry 2015
Taku Shoji Akifumi Maruyama Takanori Araki Shunji Ito Tetsuo Okujima

Preparation of 2- and 6-thienylazulene derivatives was established by the palladium-catalyzed direct cross-coupling reaction of 2- and 6-haloazulenes with the corresponding thiophene derivatives in good yield. Several thienylazulene derivatives were also used in the reaction with 2-chloroazulene derivatives in the presence of the palladium-catalyst to afford the thiophene derivatives with two a...

Journal: :Chemical communications 2007
Toshiaki Watanabe Satoshi Ueda Shinsuke Inuki Shinya Oishi Nobutaka Fujii Hiroaki Ohno

One-pot N-arylation and oxidative coupling can be promoted by a common palladium catalyst in the presence of appropriate additives: palladium-catalyzed N-arylation of anilines with aryl triflates under the standard conditions followed by addition of acetic acid under oxygen or air atmosphere afforded various types of functionalized carbazoles in good to excellent yields.

Journal: :Journal of polymer science 2023

Abstract Nickel‐ and palladium‐catalyzed insertion copolymerization of ethylene acrylate comonomers for synthesis ethylene‐acrylates copolymers have attracted much academic industrial interests remained highly challenging. This review provides an overview the developments in nickel‐ comonomers. Mechanistic interpretation metal‐catalyzed is described. Late transition metal catalysts are divided ...

Journal: :journal of the iranian chemical research 0
majid ramezani department of chemistry, faculty of science, islamic azad university, arak branch, arak, iran mohsen heidarzadeh department of chemistry, faculty of science, islamic azad university, arak branch, arak, iran fatemeh yousefi department of chemistry, faculty of science, islamic azad university, arak branch, arak, iran

a simple, rapid and efficient dispersive liquid–liquid microextraction by use of ionic liquid (il-dllme)method, followed by flame atomic absorption spectrometry (faas) was developed for the preconcentrationand determination of palladium in water samples. in this method, an appropriate mixture of acetone and octylmethyl imidazolium hexafluorophosphate was injected rapidly into the aqueous sample...

2009
David A. Kidwell

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a technique for trace elemental analysis and isotopic distribution determination at trace levels, but ICPMS cannot handle directly high concentrations of ions. Dimethylglyoxime will selectively precipitate palladium from acid solutions leaving most of the impurities in solution and allowing their quantitation by ICP-MS without dilution. B...

2014
Masato Ohashi Sensuke Ogoshi

In this review, we summarize our recent development of palladium(0)-catalyzed cross-coupling reactions of perfluoro organic compounds with organometallic reagents. The oxidative addition of a C–F bond of tetrafluoroethylene (TFE) to palladium(0) was promoted by the addition of lithium iodide, affording a trifluorovinyl palladium(II) iodide. Based on this finding, the first palladium-catalyzed c...

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