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 ...

one-pot multicomponent reaction between isatin, barbituric acid, and 6-amino-1,3-dimethyl uracil was investigated in the presence of sulfonic acid functionalized nanoporous silica (sba-pr-so3h) and resulted in the formation of spirooxindole dipyrimidines. spirooxindole unit is found in many natural products and biologically active molecules and 1,4-dihydropyridines are an important class of com...

sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...

Ionic liquid with multi-SO3H groups was employed as a catalyst for facile preparation of 1,8dioxo-decahydroacridines via the one-pot condensation of various aldehydes, 1,3-diketones with aromatic amines or ammonium acetate. Various aromatic aldehydes were utilized in the reaction and in all situations the desired product were synthesized successfully. The described novel synthesis method propos...

Selective synthesis of carbamates from amines and dimethyl carbonate were studied in the presence of various ionic liquids as catalysts. The SO3H-functionalized ionic liquid was found to be the most active catalyst among the applied ionic liquids, and nearly 100% conversion and 95% electivity were achieved when using 1,6-hexanediamine as reactant. The acid functional ionic liquid catalyst syste...

In this protocol, 3-(2-carboxybenzoyl)-1-methyl-1H-imidazol-3-ium chloride [Cbmim]Cl and sulfonic acid functionalized pyridinium chloride [pyridine-SO3H]Cl as a new, reusable, and green Brønsted acidic ionic liquid (BAIL) catalyst were synthesized and successfully used for the one-pot ring opening of epoxide with sodium azide (NaN3) in water at room temperature. Epoxides under ring-opening easi...

A heterogeneous process for the hydrolysis of bamboo into reducing sugars, a process catalyzed by biomass char sulfonic acids (BC-SO3Hs), was carried out under microwave irradiation. This transformation technology was nearly ineffective with regards to the hydrolysis of fresh bamboo because of the impeding lignin that was wrapped around the cellulose, but the hydrolysis proceeded efficiently wh...

Assimilating hydrophilic hollow polymer spheres (HPS) into Nafion matrix by a loading of 0.5 wt % led to a restructured hydrophilic channel, composed of the pendant sulfonic acid groups (–SO3H) and the imbedded hydrophilic hollow spheres. The tiny hydrophilic hollow chamber was critical to retaining moisture and facilitating proton transfer in the composite membranes. To obtain such a tiny cavi...

Co3O4/NiO@GQDs@SO3H nanocatalyst has been used as an effective catalyst for the preparation of benzopyranopyridines through a four-component reaction of salicylaldehydes, thiols and 2 equiv of malononitrile under reflux condition in ethanol. The catalyst has been characterized by FT-IR, XRD, SEM, EDS, BET, XPS, TGA and VSM. Atom economy, reusable catalyst, low catalyst loading, applicability to...