Search

In the present study, the catalytic efficiency of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogensulfate (BBSI-HSO4) as a versatile sulfonic acid-functionalized ionic liquid was demonstrated for the one-pot mechanosynthesis of pyrano[4,3-b]-pyrans using planetary ball mill at room temperature under solvent-free conditions. This efficient mechanosynthesis approach to the 4H-pyran scaffolds displays a combination of the structure–activity relationship of ionic liquids with ecological benefits of a mechanocatalytic procedure. The ionic liquid was easily recycled and reused several times with no significant loss of its catalytic activity.

A mild and efficient protocol for the one-pot synthesis of 4-amidocinnolines was developed using saccharin as a cheap and eco-friendly organocatalyst and t-butyl nitrite as a metal-free diazotization reagent. The current method has advantages such as cost effectiveness, use of the biodegradable reagents, simple experimental procedure; afford the quantitative yield of the desired products, metal- and halogen-free as well as environmentally benign conditions.

A poly(N-vinylimidazole)-catalyzed one-pot multicomponent reaction for the synthesis of 2-amino-4H-benzo[g]chromenes containing acyl group on the 4H-chromene ring has been developed. The products were obtained in generally good to excellent yields in the presence of low loading of poly(N-vinylimidazole) as a reusable basic catalyst via this synthetic strategy. Importantly, the catalyst has the unique ability of being easily separated and recycled. The products were screened for their antibacterial activity against Escherichia coli. The results of antibacterial studies showed that three 4-aroylchromene derivatives completely inhibited E. coli at 32 mg cm−3, whereas other derivatives were either moderately active or inactive up to 64 mg cm−3. Highest antimicrobial activity was observed when the phenylglyoxal hydrate was substituted with fluoro, nitro, and methoxy groups at para position.

1,1′-Butylenebis(3-methyl-3H-imidazol-1-ium) hydrogen sulfate as an efficient, halogen-free, and reusable binuclear Bronsted ionic liquid catalyzed the synthesis of tacrine analogues. This method has the advantages of high yield, clean reaction, and simple methodology. The structure of the products was confirmed by IR, 1H NMR, 13C NMR, MS, and elemental analysis. .

The chemoselective N-Boc protection of amines has been performed in the presence of catalytic amount of poly(4-vinylpyridinium) perchlorate at room temperature .and neat conditions. This new method has distinct advantages, including its excellent yields and short reaction times as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst can be reused and recycled several times without significant loss in its activity.

1,1′-Butylenebis(3-methyl-3H-imidazol-1-ium) dihydrogensulfate as an efficient, halogen-free and reusable binuclear Bronsted ionic liquid catalyzed the synthesis of pyrano[4,3-b]pyran derivatives at 60 °C under solvent-free conditions. This method has the advantages of high yield, clean reactions, simple methodology and short reaction time. The ionic liquid could be recycled without significant loss of activity. The structure of the compounds was confirmed by IR, 1H NMR, 13C NMR, mass and elemental analysis.

Succinimide sulfonic acid (SuSA) as a stable reagent is easily prepared by the reaction of succinimide with neat chlorosulfonic acid. This compound is able to catalyze the chemoselective conversion of amines to their corresponding N-Boc protected derivatives with (Boc)2O. All reactions were performed under mild conditions, giving the desired products in good to high yields.