نتایج جستجو برای: 13 dicarbonyl
تعداد نتایج: 333355 فیلتر نتایج به سال:
We have realized a Pd-catalyzed ring-opening of diazabicyclic olefins with 4-halo-1,3-dicarbonyl compounds. This reaction resulted in the formation 3(2H)-furanone-appended hydrazino cyclopentenes. The proceeds via π-allylpalladium intermediate which is attacked by active methylene species, and an intramolecular nucleophilic substitution moiety furnishes 3(2H)-furanone-substituted cyclopentene. ...
in this research, we have developed cheap recyclable and task-specific acidic ionic liquids (ails) 1-hydrogen-3-methylimidazolium hydrogen sulfate [hmim]hso4, 1-hydrogen-3-methylimidazolium chloride [hmim]cl, 2-pyrrolidonium hydrogensulfate [hnhp]hso4 and applied them in acid catalyzed synthesis of quinoxaline derivatives from 1,2-phenylendiamines and 1,2-dicarbonyl compounds. the products coul...
The development of a decarboxylative palladium-catalyzed coupling of 1,3-dicarbonyl compounds with indole, pyrrole, imidazole, and pyrazole nucleophiles via an allylic linker under neutral conditions is disclosed. This process enables the installation of an all-carbon quaternary center and new C-C and C-N bonds in a single operation. Despite the weakly acidic nature of N-heterocycles, the react...
The synthesis of the first terminal imido complex of cobalt, [PhBP3]CoN-p-tolyl, is reported. Its synthesis proceeds by oxidative group transfer from cobalt(I) upon addition of tolyl azide at room temperature. This species and a related eta1-diazoalkane adduct have been structurally characterized. The diamagnetic imido complex [PhBP3]CoN-p-tolyl reacts with CO to liberate isocyanate and the cob...
The Pd(TFA)2-catalyzed [4+1] annulation of chained or cyclic α-alkenyl-dicarbonyl compounds and unprotected primary amines for “one-pot” synthesis of pyrroles is reported here. Enamination and amino-alkene were involved in this practical and efficient tandem reaction. The annulation products were isolated in moderate to excellent yields with O2 as the terminal oxidant under mild conditions. In ...
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...
We report here a novel and easy-to-handle reductive dehalogenation of 9-bromofluorene in the presence of arylaldehydes and dicarbonyl derivatives to give the corresponding fluorenyl alcohol derivatives and Darzens epoxides as by-products in tetrakis(dimethylamino)ethylene (TDAE) reaction conditions. The reaction is believed to proceed via two successive single electron transfers to generate the...
A novel metal-free approach to construct the tetrasubstituted furans from Morita-Baylis-Hillman (MBH)-carbonates of acetylenic aldehydes has been developed. This strategy involves the cascade nucleophilic substitution/5-exo-dig-cycloisomerization of MBH-carbonates with 1,3-dicarbonyl compounds to give uniquely substituted 2-furan-3-yl acrylates. Additionally, the obtained furan adducts open a n...
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 ...
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