A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in w...

the epoxidation of olefins with tetra n-butylammonium periodate, n-bu4/nio4, is catalyzed by six different tetrakis (4-substituted phenyl) porphyrinatomanganese(iii) acetate, mn(t4-xpp)oac, complexes in the presence of imidazole as an axial ligand with low to high yields and complete selectivity at room temperature. while the electronic effects of the highly electron-withdrawing no2 substituent...

silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1h)-ones. this intramolecular aza michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. the catalyst is reusable without significant decreases in its activity after four t...

an atom-efficient, eco-friendly, solvent-free, high yielding, multicomponent green strategy to synthesize triazolo[1,2-a]indazole-triones derivatives by the one-pot condensation of aldehyde, dimedone, and phenyl urazole is presented. a series of different substituted aromatic aldehydes including either electron-withdrawing or electron-donating groups used in this reaction participated well and ...

5-acetyl-6-methyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones were synthesized in good to excellent by one-pot three-component Biginelli condensation in the presence of ammonium salt [Et3NH][HSO4] as an inexpensive and green catalyst under solvent-free conditions. High yields, short reaction time, easy work-up, a green environment which requires no toxic o...

An atom-efficient, eco-friendly, solvent-free, high yielding, multicomponent green strategy to synthesize triazolo[1,2-a]indazole-triones derivatives by the one-pot condensation of aldehyde, dimedone, and phenyl urazole is presented. A series of different substituted aromatic aldehydes including either electron-withdrawing or electron-donating groups used in this reaction participated well and ...

Silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1H)-ones. This intramolecular aza Michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. The catalyst is reusable without significant decreases in its activity after four t...

a green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of β-naphthol, aldehyde, and 6-amino-1,3-dimethyluracil using l-proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100 °c is described. in this study, several types of aromatic aldehyde, containing electron-withdrawing groups as well ...

an efficient and eco-friendly protocol for the preparation of 2-amino-4h-chromenes employing a multi-component, one-pot condensation reaction between aromatic aldehydes, malononitrile and1-naphthol has been developed. the reaction of 1-naphthol with malononitrile and various aromatic aldehydes was carried out in water-ethanol (1:1) at reflux using 20 mol% of diammonium hydrogen phosphate as cat...