نتایج جستجو برای: bromides

تعداد نتایج: 13171  

Journal: :Organic letters 2008
Bruce H Lipshutz David W Chung Brian Rich

Cross-coupling reactions between lipophilic terminal alkynes and aryl bromides can be catalyzed by ligated Pd, in the absence of copper, in pure water at ambient temperatures. Small amounts of the nonionic amphiphile PTS assist by virtue of nanometer micelles formed spontaneously in an aqueous medium.

Journal: :Chemical communications 2009
Tongjie Hu Thomas Schulz Christian Torborg Xiaorong Chen Jun Wang Matthias Beller Jun Huang

A convenient and general palladium-catalyzed coupling reaction of aryl bromides and chlorides with phenols was developed. Various functional groups such as nitriles, aldehydes, ketones and esters are well tolerated and the corresponding products are obtained in good to excellent yield.

Journal: :Organic & biomolecular chemistry 2015
Wanfang Li Xiao-Feng Wu

We developed a palladium-catalyzed carbonylative Sonogashira reaction with aryl triazenes and alkynes as substrates and methanesulfonic acid as the additive. A series of α,β-ynones were synthesized by this alternative procedure. Notably, bromides, iodides and hydroxyl groups could be well-tolerated under these reaction conditions.

2014
Stig D. Friis Troels Skrydstrup Stephen L. Buchwald

A palladacyclic precatalyst is employed to cleanly generate a highly active XantPhos-ligated Pd-catalyst. Its use in low temperature aminocarbonylations of (hetero)aryl bromides provides access to a range of challenging products in good to excellent yields with low catalyst loading and only a slight excess of CO. Some products are unattainable by traditional carbonylative coupling.

Journal: :Water 2023

Bromate formation is a complex process that depends on the properties of water and ozone used. Due to fluctuations in quality, surface waters require major adjustments treatment process. In this work, we investigated how time year, dose duration, ammonium affect bromides, bromates, absorbance at 254 nm (UV254), near-infrared (NIR) spectra, fluorescent components (humic-like tyrosine-like) durin...

Journal: :ACS Sustainable Chemistry & Engineering 2021

Buchwald–Hartwig amination is one of the most important methods for synthesis N-arylamines and widely employed potential pharmaceuticals, natural products, other fine chemicals. The reaction usually uses a Pd(0) catalyst such as Pd(dba)2 (±)-BINAP in presence base, toluene commonly used solvent. However, there are significant safety, toxicological, environmental hazards associated with use tolu...

Journal: :Journal of the American Chemical Society 2010
Xiaoqiang Shen Alan M Hyde Stephen L Buchwald

The palladium-catalyzed conversion of aryl and vinyl triflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl, and vinyl halides can be prepared via this method in good to excellent yields.

Journal: :The Journal of organic chemistry 2010
Debabrata Maiti Stephen L Buchwald

Cu-catalyzed O-arylation of phenols with aryl iodides and bromides can be performed under mild condition in DMSO/K(3)PO(4) with use of picolinic acid as the ligand for copper. This method tolerates a variety of functional groups and is effective in the synthesis of hindered diaryl ethers and heteroaryl ethers.

Journal: :Chemical communications 2007
Gagan Chouhan Dashan Wang Howard Alper

Magnetic nanoparticle-supported proline ligand was prepared and used for the CuI catalyzed Ullmann-type coupling reactions of aryl/heteroaryl bromides with various nitrogen heterocycles to form the corresponding N-aryl products in good to excellent yields; furthermore, this magnetic nanoparticle-supported proline ligand could be readily separated using an external magnet and reused without sign...

Journal: :Chemical communications 2012
Bryden A F Le Bailly Mark D Greenhalgh Stephen P Thomas

An iron-catalysed, hydride-mediated reductive cross-coupling reaction has been developed for the preparation of alkanes. Using a bench-stable iron(II) pre-catalyst, reductive cross-coupling of vinyl iodides, bromides and chlorides with aryl- and alkyl Grignard reagents successfully gave the products of formal sp(3)-sp(3) cross-coupling reactions.

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