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 ...

a simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([hmim]hso4) as a green, efficient and reusable catalyst. using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages of this method.

a novel and safe method for nitration of phenols, anilines and other aromatic compounds has beenfound to be feasible with alumina sulfuric acid (asa) as catalyst and mg (no3)2.6h2o as nitrating agent inneat water as solvent. the use of water makes this method compatible with the green chemistry approach

an efficient one-pot condensation for the synthesis of 1,8-dioxo-octahydroxanthene is  achieved through a condensation of aryl aldehydes and 5,5-dimethyl-1,3-cyclohexandione in the presence of  nbs. this method enjoys several advantages such as low cost, simple work up procedure and safe reaction condition. in addition, water was chosen as a green solvent.

cuo-ceo2 nanocomposite is reported as a green and highly efficient recyclable catalyst for the multicomponent  synthesis of 3,4-dihydropyrimidin-2(1h)-ones/thiones under solvent-free conditions. the catalyst was synthesized by co-precipitation method and characterized by xrd, bet specific surface area, fesem and eds analysis.

in this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1h)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using al-mcm-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. the advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.

4-dodecylbenzenesulfonic acid (dbsa) has been shown to be an efficient, mild, green, stable and chemoselective brønsted acid catalyst for the synthesis of 1, 1-diacetates (acylals) of aldehydes under solvent-free conditions. the mild condition, eco-friendly, excellent yields, short reaction times and using an easily available, inexpensive and reusable catalyst are important features of this met...

Pyridinium based ionic liquids derived from β-picoline and n-alkylbromides were synthesized by a simple procedure at ambient temperature and then characterized. These neutral ionic liquids were investigated for their dual role as the solvent and promoter for the selective synthesis of a series of N-monomethylanilines using dimethylcarbonate as the methylating agent. A solvent free gree...

This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...

[B(OH)3]0.78[B(OH)2(OSO3H)]0.22 or (BSA) was simply prepared by addition of chlorosulfonic acid to commercial boric acid at room temperature. This cheap and green solid acid was used as an efficient catalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.