نتایج جستجو برای: 3 dicarbonyl compounds

تعداد نتایج: 1987990  

Journal: :Organic & biomolecular chemistry 2010
Xianpei Wang Bing Han Junyan Wang Wei Yu

The N-substituted anilines 1 react readily with phenyliodonium ylides 2 derived from 1,3-dicarbonyl compounds in the presence of a catalytic amount of BF(3).Et(2)O, forming the C-N coupling products 3, which are precursors for the synthesis of indoles. On the basis of this result, the direct synthesis of indoles from 1 and 2 under thermal conditions and photochemical conditions was explored. Th...

Journal: :Organic & biomolecular chemistry 2015
Yeming Ju Di Miao Ruiyang Yu Sangho Koo

One pot syntheses of furan, thiophene, and pyrrole were accomplished by oxidative deacetylation using Mn(III)/Co(II) catalysts and the Paal-Knorr reaction from 1,5-dicarbonyl compounds, which are prepared from the conjugate addition of ethyl acetoacetate to α,β-unsaturated carbonyl compounds. The oxidative deacetylation and reductive cyclization of β-ketoesters derived from ethyl acetoacetate a...

2013
A. M. Elmaghraby I. A. Mousa A. A. Harb M. Y. Mahgoub

Synthesis of 3,4-dihydropyrimidin-2(1H)-one and 3,4-dihydropyrimidin-2(1H)-thione derivatives from aldehydes, 1,3-dicarbonyl derivatives and urea or thiourea using granite and quartz as new, natural and reusable catalysts. Some of the 3,4-dihydropyrimidin-2(1H)-thione derivatives were used to prepare new heterocyclic compounds. The antimicrobial activity of selected examples of the synthesized ...

Journal: :ACS Sustainable Chemistry & Engineering 2022

Pyrroles are important compounds present in biological systems, used for drug synthesis and material chemistry. A typical strategy the pyrrolic ring formation is centered on Paal–Knorr reaction, where 1,4-dicarbonyl react with amines giving N-substituted pyrrole derivatives. Often, main problem of this approach availability appropriate carbonyl compounds. Here, we report a sustainable carboxyli...

Journal: :Molecules 2023

Free radicals and oxidants may cause various damages both to the lifeworld different products. A typical solution for prophylaxis of oxidation-caused conditions is usage antioxidants. Among them, classes are found—polyphenols, conjugated polyalkenes, some sulfur nitrogen derivatives. Regarding active site in molecules, a widely discussed group compounds 1,3-dicarbonyl compounds. them natural (e...

Journal: :journal of the iranian chemical research 0
muhammed basheer ummathur department of chemistry, kahm unity women’s college, manjeri, kerala-676122, india anjali krishnan department of chemistry, kahm unity women’s college, manjeri, kerala-676122, india perumpalli ummer department of chemistry, university of calicut, kerala-673635, india

the coupling of tetrazotised 1,8-diaminonaphthalene with 1,3-dicarbonyl compounds [acetylacetone,methylacetoacetate and acetoacetanilide] yielded a new series of tetradentate ligand systems. analytical, ir,1h nmr and mass spectral data indicate that the compounds exist in the intramolecularly hydrogen bondeddihydrazone form. dibasic tetradentate n2o2 coordination of these compounds in their [ml...

2012
Kamal Usef Sadek Ramadan Ahmed Mekheimer Tahany Mahmoud Mohamed Moustafa Sherief Moustafa Mohamed Hilmy Elnagdi

The multicomponent reaction of 5-aminopyrazole derivatives with cyclic 1,3-dicarbonyl compounds and dimethylformamide dimethylacetal (DMFDMA) in DMF at 150 °C under controlled microwave heating afforded regioselectively 8,9-dihydropyrazolo[1,5-a]quinazolin-6(7H)-ones 6 rather than the corresponding dihydropyrazolo[5,1-b]quinazolin-8(5H)-ones 4.

Journal: :Chemical communications 2014
Stacey L McDonald Qiu Wang

Selective α-amination and α-acylation of esters and amides have been developed, employing O-acylhydroxylamines as a dually reactive aminating and acylating reagent. Treatment of zinc enolates with O-acylhydroxylamines provides solely 1,3-dicarbonyl compounds under mild conditions. Introduction of a copper catalyst into the system shifts the reactivity entirely, yielding α-amination products exc...

Journal: :Organic letters 2015
Miles Kenny Jeppe Christensen Simon J Coles Vilius Franckevičius

A palladium-catalyzed chemo- and regioselective coupling of 1,3-dicarbonyl compounds via an allylic linker has been developed. This reaction, which displays broad substrate scope, forms two C-C bonds and installs two all-carbon quaternary centers. The regioselectivity of the reaction can be predictably controlled by utilizing an enol carbonate of one of the coupling partners.

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