نتایج جستجو برای: catalyst free

تعداد نتایج: 553796  

Xiaocui Deng Xiaoyun Hu Zhongqiang Zhou,

A simple and environmentally benign procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol with aromatic aldehyde in the presence of [Et3NH][HSO4] as an acidic ionic liquid catalyst under solvent-free conditions has been developed. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused s...

An environmentally friendly, one-pot, three-component synthesis of 8,10-dimethyl-12-aryl-12H-naphtho[1′,2′:5,6]pyrano[2,3-d]pyrimidine-9,11-diones was achieved via coupling aromatic of aldehydes, β-naphthol and 6-amino-1,3-dimethyl uracil in the presence of formic acid as a catalyst under solvent-free conditions at 90 °C. This method has several advantages, such as efficiency, good yield, short...

A simple, efficient, and cost-effective procedure for the N-tert-butoxycarbonylation and N-formylation of amines (primary, secondary) respectively, with di-tert-butyl dicarbonate and 85% aqueous formic acid under solvent-free condition using B(OSO3H)3/SiO2 (SBSA) as a heterogeneous and recyclable catalyst has been developed. We demonstrated that the resulting catalyst is applicable to various a...

Journal: :iranian journal of catalysis 2016
surekha n. deshmukh jitendra b. gujar ramrao a. mane murlidhar s. shingare

a rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. the condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. stannous chloride was...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2010
ghodsi mohammadi ziarani ali reza badiei yeganeh khaniania mahbobeh haddadpour

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 ...

Journal: :iranian journal of catalysis 2014
bibi fatemeh mirjalili abdolhamid bamoniri fahimeh kalantari

[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.

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2005
ahmad shaabani ayoob bazgir sakineh arab ameri masoumeh sharifi kiasaraie sima samadi

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.

Journal: :iranian journal of catalysis 2012
ahmed ali hullio ghulam murtaza mastoi

nicotine-based ionic liquid has been used as a green catalyst for pyridine-catalyzed huisgen reaction. it promoted addition of dimethylacetylenedicarboxylate to aldehydes or n-tosyl imines leading to efficient synthesis of 2-benzoylfumarates and 1-azadienes respectively under pyridine free odorless ionic liquid conditions. the improved results were obtained in terms of enhanced yields, with min...

Journal: :journal of nanostructures 2012
j. safaei-ghomi m. a. ghasemzadeh

the efficient and environmentally friendly method for the one-pot synthesis of polyhydroquinolines has been developed in the presence of cuo nanoparticles. the multi-component reactions of aldehydes, dimedone, ethyl acetoacetate andammonium acetate were carried out under solvent-free conditions to afford some polyhydroquinoline derivatives. this method provides several advantages including high...

Journal: :iranian journal of catalysis 2014
hossein naeimi zahra sadat nazifi

efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by knoevenagel condensation, michael addition and cyclodehydration of dimedone. this reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific brønsted acidic ionic liquid under solvent free conditions. the catalyst could be recycled five times without si...

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