نتایج جستجو برای: carbonyl compound

تعداد نتایج: 139449  

Marziyeh Bagheri Mostafa Karimkoshteh,

Nano silica-H2SO4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. Ketoximes are converted to amides by Beckmann rearrangement in the presence of nano silica-H2SO4. The reactions are carried out in solvent-free conditions under microwave irradiation (600 W) within 50-120 sec in good yields.

Journal: :Synlett : accounts and rapid communications in synthetic organic chemistry 2009
Chun-Yu Ho Kristin D Schleicher Timothy F Jamison

Recent advances using nickel complexes in the activation of unactivated monosubstituted olefins for catalytic intermolecular carbon-carbon bond-forming reactions with carbonyl compounds, such as simple aldehydes, isocyanates, and conjugated aldehydes and ketones, are discussed. In these reactions, the olefins function as vinyl- and allylmetal equivalents, providing a new strategy for organic sy...

Journal: :Molecules 2011
Serkan Yavuz Hamdi Ozkan Naki Colak Yilmaz Yildirir

A simple, fast, efficient and eco-friendly procedure was developed for the synthesis of alkyl and aryl-N-methylnitrones. The corresponding nitrones of aromatic aldehydes, aliphatic aldehydes and alicyclic carbonyl compounds were prepared from N-methylhydroxylamine hydrochloride and Na2CO3-Na2SO4 by simply grinding at room temperature without using solvent.

Journal: :Journal of the American Chemical Society 2010
Yujiang Mei Prabani Dissanayake Matthew J Allen

The development of aqueous methods for generating enantiopure β-hydroxy carbonyl compounds is an important goal because these subunits compose many bioactive compounds and the ability to synthesize these groups in water has environmental and cost benefits. In this communication, we report a new class of ligands for aqueous, lanthanide-catalyzed, asymmetric Mukaiyama aldol reactions for the synt...

2017
Yu-Chi Chen Chien-Chi Wu Wei-Ting Liao Ling-Jun Liu

Abstract: A reusable PdCl2(NH3)2/cationic 2,2′-bipyridyl system was used to catalyze the double Mizoroki-Heck reaction of aryl iodides with electron-deficient alkenes in water in the absence of inert gas, giving β,β-diarylated carbonyl derivatives in good to excellent yields. The formation of unsymmetrical β,β-diarylated alkenes were also studied by coupling aryl iodides with the corresponding ...

Journal: :Chemical communications 2011
Haiting Cai Zheliang Yuan Weidong Zhu Gangguo Zhu

Described herein is a Pd-catalyzed haloallylation of aromatic ynol ethers and allyl chlorides, allowing facile access to (1E)-α-chloroenol ethers in a highly regio- and stereoselective manner. The synthetic utility of this method is demonstrated well by the synthesis of the stereodefined multisubstituted enol ethers and α-allylated carbonyl compounds.

Journal: :Organic & biomolecular chemistry 2011
Cheng-Yan Ni Sha-Sha Kan Quan-Zhong Liu Tai-Ran Kang

Highly diastereoselective and enantioselective catalytic capture of chiral zinc enolates using nitroolefins as electrophiles is described. The tandem products γ-nitro ketones were obtained in good yields with high diastereoselectivities and enantioselectivities. The γ-nitro ketones were readily hydrogenated to the optically enriched and diastereomerically pure chiral pyrrolidines with four cont...

Journal: :Organic & biomolecular chemistry 2013
Atul Goel Gaurav Taneja Ashutosh Raghuvanshi Ruchir Kant Prakas R Maulik

A new general methodology for the synthesis of various functionalized privileged oxygen heterocyclic scaffolds, viz. pyrones, coumarins, and benzannulated coumarins, is developed. The synthesis proceeds through carbanion-induced ring transformation of lactones with various methylene carbonyl compounds followed by DDQ-mediated unprecedented oxidative cleavage of oxaylidenes intermediates. Studie...

2012
Jonas Altnöder Juhyon J Lee Katharina E Otto Martin A Suhm

Carbohydrates are used in nature as molecular recognition tools. Understanding their conformational behavior upon aggregation helps in rationalizing the way in which cells and bacteria use sugars to communicate. Here, the simplest α-hydroxy carbonyl compound, glycolaldehyde, was used as a model system. It was shown to form compact polar C 2-symmetric dimers with intermolecular O-H⋅⋅⋅O=C bonds, ...

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