A green and convenient method for the synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8,13-diones and spiro[dibenzo[a,i]-xanthene-14,3'-indoline]-2',8,13-triones in the presence of a catalytic amount of cellulose sulfuric acid (CSA) as an efficient biopolymer-based catalyst under solvent-free conditions at 100 °C is described. The condensation reactions of β-naphtol, 2-hydroxynaphthalene-1,4-dion...

for the first time lactic acid was applied as an efficient and green catalyst for the one-pot three-component synthesis of amidoalkyl naphthols via the condensation between arylaldehydes, 2-naphthol and amides or urea under thermal solvent-free conditions in good to excellent yields. we have demonestrated a mild and efficient eco-friendly tandem synthesis of amidoalkyl naphthols using lactic ac...

cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...

A protocol for the synthesis of 1,4-dihydropyridines (Hantzsch type-products) was developed by means of a three-component condensation of an aldehyde, a β-dicarbonyl compound, ammonium acetate and nano Al2O3/KF as catalyst. This reaction was carried out under different conditions including i) solvent-free ii) and reflux in different solvents. In all conditions, the desired products were obtaine...

Herein, it has been shown that the bismuth ferrite magnetic nanoparticles (BFO-MNPs) are new, efficient and recyclable catalysts for the synthesis of polyhydroquinoline derivatives by the Hantzsch reaction. The one-pot four-component cyclocondensation reaction of dimedone, aromatic aldehydes, ethyl acetoacetate and ammonium acetate was carried out under solvent-free conditions. The...

Improved catalytic durability towards acidic oxygen reduction reaction is achieved by using a Pt-free and Fe-free single-atom catalyst based on Mn, Co N co-doped carbon (MnCo–N–C), compared with (Co–N–C) catalyst.

Freshly prepared ZnO nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. The conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with ZnO nanoparticles under solvent-free condition. The procedure was carried out und...

CuO-CeO2 nanocomposite is reported as a green recyclable catalyst for the chemoselective synthesis of pentaerythritol diacetals from aromatic aldehydes under solvent-free conditions. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, FESEM and EDS analysis. This procedure provides some advantages such as simple work-up, clean procedure, ...

An efficient protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via multi-component coupling reaction of aromatic aldehydes, β-ketoester and urea or thiourea under solvent-free conditions using Silica Supported Barium Chloride as a catalyst is described. All prepared compounds with melting points, IR,1H NMR and 13C NMR were identified. High yields, mild conditi...

     Cellulose was applied as a reusable and green catalyst for the facile four-component synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile derivatives using hydrazine monohydrate, ethyl acetoacetate, malononitrile and aryl aldehydes, under solvent-free and thermal conditions. The use of non-toxic and inexpensive catalyst, short reaction time, clean w...