نتایج جستجو برای: βunsaturated ketones moieties

تعداد نتایج: 19705  

Journal: :Chemical communications 2014
Yunhe Lv Yan Li Tao Xiong Yu Lu Qun Liu Qian Zhang

nBu4NI-Catalyzed oxidative imidation of ketones and imides for the synthesis of α-amino ketones were realized for the first time. The methodology is characterized by its wide substrate scope even for acetone with readily available phthalimide, saccharin and succinimide, which opens a new pathway for direct imidation of ketones.

Journal: :Chemical communications 2014
Shinji Ogawa Yasushi Obora

Iridium-catalyzed selective α-dimethylation and α-methylation of ketones or phenylacetonitriles, using methanol as the methylating agent, were achieved. In addition, three-component cross α-methyl-alkylation was successfully performed using methyl ketones with methanol and primary alcohols with long-chain alkyl groups. This method provides a very convenient direct route to α-methylated ketones,...

Journal: :Chemical communications 2014
Ahmed R Akhbar Vijay Chudasama Richard J Fitzmaurice Lyn Powell Stephen Caddick

In this communication we describe a novel strategy for the formation of valuable diaryl and aryl alkyl ketones from acyl hydrazides. A wide variety of ketones are prepared and the mild reaction conditions allow for the use of a range of functionalities, especially in the synthesis of diaryl ketones.

Journal: :Organic & biomolecular chemistry 2016
Daniel J Leng Conor M Black Graham Pattison

Difluoromethyl ketones are an under-studied class of ketones which have great potential as useful building blocks for materials and drug design. Here we report a simple and convenient synthesis of this class of compounds via a one-pot difluorination/fragmentation of 1-trifluoromethyl-1,3-diketones which should now allow the chemistry of difluoromethyl ketones to be fully developed.

Journal: :Organic & biomolecular chemistry 2006
David J Fox Daniel Sejer Pedersen Stuart Warren

alpha-Diphenylphosphinoyl ketones are selectively and sequentially alkylated at the alpha-position. Double lithiation and selective alkylation occurs at the less stabilised gamma-position. Dephosphinoylation of the alkylation products gives ketones. Mono-alkylation is selective, highly crystalline intermediates are formed and a one-pot strategy is possible. The method is ideally suited for the ...

Journal: :Organic & biomolecular chemistry 2012
Jianfeng Xu Shugao Zhu Luling Wu Xian Huang

A homo-Michael addition reaction of lithium selenolates with 1-(1-alkynyl)cyclopropyl ketones and the subsequent reaction with electrophiles such as PhSeBr, NFSI and NCS is reported. Based on the nature of electrophiles, this reaction may afford highly substituted 1,2-allenyl ketones or furans (E(+) = PhSe(+)) and 2-alkynyl ketones (E(+) = F(+), Cl(+), active halides) as the final products, res...

Journal: :Chemical communications 2014
Tang-Po Yang Qiang Li Jin-Hong Lin Ji-Chang Xiao

Boron trihalide-promoted ring-opening reactions of gem-difluorocyclopropyl ketones to give the corresponding β-trifluoromethyl ketones and β-halodifluoromethyl ketones were described. It was found that boron trihalides act as both Lewis acids and nucleophiles and the proximal bond prefers to cleave in this transformation.

Journal: :Organic & biomolecular chemistry 2016
Begur Vasanthkumar Varun Karthik Gadde Kandikere Ramaiah Prabhu

α-Sulfenyl ketones are potential precursors which find a variety of applications in organic synthesis. Their typical synthesis requires pre-functionalized starting materials and two to three step synthetic sequences. In addition, the selective pre-functionalization of unsymmetrical ketones is a challenge, which limits the synthesis of the desired sulfenylated ketones. To overcome these disadvan...

2013
Hu Wang Li Li Xing-Feng Bai Jun-Yan Shang Ke-Fang Yang Li-Wen Xu

A simple method has been developed for the reductive deoxygenation of aromatic ketones and benzylic alcohols in the presence of polymethylhydrosiloxane (PMHS). The reductive deoxygenation of aromatic ketones and benzylic alcohols, including secondary alcohols, to the corresponding methylene hydrocarbons has been achieved in good to excellent yields using palladium chloride (PdCl2) as catalyst a...

Journal: :Chemical communications 2011
Kamala Kunchithapatham Chad C Eichman James P Stambuli

The synthesis of unsymmetrical diaryl ketones via the Fukuyama coupling of thioesters and organozinc reagents is described. Typically, the synthesis of diaryl ketones using this methodology provides low yields. The simple complex, Pd(dba)(2), was found to convert a variety of aryl thioesters to diaryl ketones in good yields.

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