The synthesis of pharmaceutically and biologically active 2-amino-4H-chromenes was described using TiO2/nanoclinoptilolite (TiO2/NCP) as an efficient nanocatalyst under solvent-free condition. The TiO2/NCP was fabricated through modification of NCP with HDTMA, then the surface modified NCP was impregnated with titanium tetrachloride solution. Finally, the materi...

In this research, a Brønsted acidic ionic liquid namely N1,N1,N2,N2-tetramethyl-N1,N2-bis(sulfo)ethane-1,2-diaminium chloride {[TMBSED][Cl]2} was employed as a highly efficient catalyst for the solvent-free production of some nitrogen- and oxygen-containing heterocyclic compounds including: (i) polyhydroquinolines (from arylaldehydes, dimedone, β-ketoesters and ammonium acetate), (ii) 3,4-dihyd...

-A simple, efficient, and general method has been developed for the chemoselective acetalization of aldehydes with 1,3-propanediol, 1,2-ethanediol and trimethyl orthoformate in the presence of solid lithium perchlorate under solvent-free conditions. Both cyclic and acyclic acetals of aldehydes were obtained under environmentally benign conditions in good to excellent yields.

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.

nano-silica supported titanium tetrachloride (ticl4.sio2) was prepared and used as an acid catalyst for the 14-aryl or alkyl-14h-dibenzo[a,,j]xanthenesreaction under solvent-free conditions. compared to the classical 14-aryl or alkyl-14h-dibenzo[a,j]xanthenesreaction conditions, this method consistently has the advantage of excellent yields, mild reaction conditions, ease of workup, survival of...

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...

This work described a simple and efficient method for the synthesis of 1-azabicyclo[3.1.0]hexane-3-ene derivatives. arylidenmalononitriles and hydroxylamine hydrochloride in the presence of NaOH, under microwave irradiation and solvent-free conditions produced the titled compounds in good to excellent yields. Using of simple chemicals, short reaction times, and solvent-free conditions, high yie...

[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.

alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1h)-ones in high yields at 80 °c. our results showed that biginelli reaction not only is ph dependent, but the cation of catalyst plays an important role.

silica-bonded n-propyltriethylene-tetramine (sbnptt) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4h-chromenes. chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oc under solvent-free conditions. the heterogeneous solid base showed much the same efficiency when u...