knoevenagel condensation between barbituric acid and aldehyde was investigated in the presence of sulfonic acid functionalized nanoporous silica (sba-pr-so3h) and resulted in the formation of arylidene and bis-arylidene barbiturates. excellent yields and short reaction times are related to the high efficiency of sba-pr-so3h that the reactions take place easily in its nano-pores. sba-pr-so3h as ...

Highly functionalized multisubstituted 1,4-dihydropyridines 5 have been concisely synthesized in moderate to good yields via L-proline-catalyzed one-pot multicomponent reactions (MCRs) of alkynoates or alkynones 1, amines 2, beta-dicarbonyl compounds 3 and aldehydes 4 under mild conditions. The MCR process involves hydroamination/Knoevenagel condensation/Michael-type addition/intramolecular cyc...

As part of our project devoted to the synthesis of heterocycles including thiazole rings, some new 5-arylidene-2-thioxo-3-N-arylthiazolidin-4-ones were synthesized by Knoevenagel condensation. An interesting feature of these compounds is that their chirality is induced by that of their 3-N-(2-alkyloxyaryl)-2-thioxothiazolidin-4-one precursors, which in turn is due to the presence of a C2 axis o...

The Knoevenagel condensation of 1,3-dihydro-2H-indol-2-one with ferrocene carboxaldehyde afforded an approximate 2:1 mixture of the geometrical isomers (E)- and (Z)-3-ferrocenylmethylidene-1,3-dihydro-2H-indol-2-one respectively in an overall 67% yield; the air and solution-stable isomers were readily separated by preparative thin layer chromatography and their structures were unequivocally elu...

The covalent attachment of piperazine onto the inner walls of a microreactor using glycidyl methacrylate polymer brushes has been demonstrated. The piperazine-containing polymer brushes were first grown on a flat silicon oxide surface and were characterized by contact angle, Fourier transform infrared (FT-IR), ellipsometry, and X-ray photoelectron spectroscopy (XPS). The applicability of the ca...

Two Cd(ii) metal-organic frameworks were synthesized from the NH-functionalized dicarboxylate ligand 9H-carbazole-2,7-dicarboxylic acid (2,7-H2CDC). Compound , [Cd4(CDC)4(DMF)4]·4DMF·4H2O, displays 2D square grid networks based on novel tetranuclear [Cd4(COO)8] secondary building units (SBUs) and pairwise CDC(2-) linkers. Compound , (H3O)2[Cd3(2,7-CDC)4]·3DMF·4H2O, is also based on 4-connected ...

A simple, efficient, and green practical approach to Knoevenagel condensation of malononitrile and different aldehydes has been developed using an ionic liquid functionalized on Fe3O4 magnetic nanoparticles as heterogeneous catalyst. This nanostructural catalyst has also been applied for the synthesis of 4H-benzo[b]pyran derivatives in water at room temperature in short reaction time. All of th...