نتایج جستجو برای: biginelli reaction
تعداد نتایج: 412492 فیلتر نتایج به سال:
Montmorillonite modified is an efficient environmental friendly catalyst under one-pot-three-component synthesis of 3,4-dihydropyrimidine-2(1H) ones. The preparation was performed with an aldehyde, 1,3-dicarbonyl compounds, urea or thiourea under solvent-free conditions. In comparison with the other methods of Biginelli reaction, this new method has short reaction time inexpensive catalyst and ...
An effective one-pot synthesis of dihydropyrimidinonoes in solvent free conditions using CuCl2 as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde derivatives, 1,3-dicarbonyl compounds and urea is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green protocol.
An enantioselective Biginelli reaction has been developed by using a bifunctional primary amine-thiourea-TfOH (BPAT·TfOH) as a chiral phase-transfer catalyst and t-BuNH(2)·TFA as an additive in saturated brine at room temperature. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 99% ee under mild conditions. A plausible transition state has been proposed ...
For the first time, chiral sulfoximine derivatives have been applied as asymmetric organocatalysts. In combination with a thiourea-type backbone the sulfonimidoyl moiety leads to organocatalysts showing good reactivity in the catalytic desymmetrization of a cyclic meso-anhydride and moderate enantioselectivity in the catalytic asymmetric Biginelli reaction. Straightforward synthetic routes prov...
A green methodology for the development of the synthesis of dihydropyrimidinones via a clean multi-component Biginelli reaction by using cyclohexane-1,4-diyl bis (hydrogen sulfate) (CDBH) as an effective catalyst in water and solvent-free conditions was reported. This sulfonated catalyst is an efficient and environmentally benign homogeneous catalysts which characterized by using different tech...
A simple, efficient and cost effective method is described for the synthesis of Biginelli type heterocyclic compounds of dihydropyrimidinones analogous. They were prepared from a reaction mixture consisting of substituted benzaldehydes, thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst. The procedure for the preparation of the compounds is environmentally benign and ...
A series of novel alkynyl substituted 3,4-dihydropyrimidin-2(1H)-one (DHPM) derivatives were designed, synthesized and evaluated in vitro as potential inhibitors of chorismate mutase (CM). All these compounds were prepared via a multi-component reaction (MCR) involving sequential I2-mediated Biginelli reaction followed by Cu-free Sonogashira coupling. Some of them showed promising inhibitory ac...
The X-ray structural characterization of tritylphosphonic acid, Ph3CPO3H2 (), reveals that it possesses three different structural forms (a hexameric cage, a two-dimensional polymeric sheet and a dimer) depending upon the solvent used for crystallization. The reaction of cerium nitrate with under solvothermal conditions afforded a molecular dinuclear Ce(III) phosphonate, [Ce2{Ph3CPO2(OEt)}4(NO3...
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