硅胶功能化的N-丙哌嗪固载钯纳米粒子作为有效的多相催化剂用于氰化反应(英文)

An efficient heterogeneous Pd catalytic system has been developed, based on immobilization of Pd nanoparticles (PNPs) on a silica-bonded N-propylpiperazine (SBNPP) substrate. The SBNPP substrate effectively stabilizes the PNPs and improves their stability against aggregation. The catalytic activity of this catalyst was investigated in the cyanation of aryl halides with K4[Fe(CN)6 ] as the cyanide source. The catalyst could be recycled several times without appreciable loss of catalytic activity.     

硅胶键合N-丙基二乙烯氨基磺酸作为可回收固体酸催化剂催化合成α-氨基腈(英文)

Silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) is employed as a recyclable catalyst to synthesize α-aminonitriles. These syntheses involved one-pot condensation of an aldehyde, an amine, and trimethylsilyl cyanide under mild reaction conditions at room temperature. SBPDSA was recycled seven times in the condensation of benzaldehyde, aniline, and trimethylsilyl cyanide without reduction of its catalytic activity.     

活性炭负载硫化锡纳米颗粒作为高效可重复使用Lewis酸催化剂催化三组分一锅法合成4H-吡喃[2,3-c]吡唑衍生物(英文)

Tin sulfide nanoparticles(SnS -NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon(AC) and were investigated using field-emission scanning electron mi-croscopy(FE-SEM), transmission electron microscopy(TEM), X-ray diffraction, reflective ultravio-let-visible spectrophotometry, and spectrofluorimetry. Calculations based on the SEM and TEM images showed that the sizes of the SnS -NPs immobilized on the AC were 30–70 nm. The prepared nanocomposite was used as a heterogeneous Lewis acid catalyst for the three-components one-pot synthesis of 4H-pyrano[2,3-c]pyrazole derivatives in ethanol at 80 ℃. The reactions were efficiently performed in the presence of the prepared catalyst in short reaction times, and gave the desired products in high yields. This catalyst can be easily recovered by simple filtration and recycled up to eight consecutive times without significant loss of its efficiency.     

硅胶键合的N-丙基三亚乙基四胺氨基磺酸作为可回收固体酸催化剂催化合成2-氨基-4,6-二芳基烟腈(英文)

A simple and efficient procedure for the preparation of silica-bound N-propyl triethylenetetramine sulfamic acid(SBPTETSA) by the reaction of silica-bound N-propyl triethylenetetramine(SBPTET) with chlorosulfonic acid in chloroform is described.Silica-bound N-propyl triethylenetetramine sulfamic acid was employed as a recyclable catalyst for the synthesis of 2-amino-4,6-diarylnicotinonitriles from the multi-component reaction of an acetophenone derivative,an aromatic aldehyde,malononitrile,and ammonium acetate under solvent-free conditions at 100 °C.The heterogeneous catalyst was recycled for five consecutive runs in the optimized multi-component reaction of 4-chloroacetophenone,4-chloroenzaldehyde,malononitrile,and ammonium acetate without significant loses to its catalytic activity.     

加热与超声辐照条件下4-(丁二酰亚胺基)-1-丁烷磺酸Brnsted酸催化剂催化吡喃并[4,3-b]吡喃衍生物合成(英文)

4-(Succinimido)-1-butane sulfonic acid was shown to be an efficient and reusable Brnsted acid catalyst for the synthesis of pyrano[4,3-b]pyran derivatives using thermal and ultrasonic conditions. The catalyst was prepared by mixing succinimide and 1,4-butanesultone, which is simpler and safer than the preparation of succinimide sulfonic acid. This method has the advantages of high yield, clean reaction, simple methodology, and short reaction time. The catalyst can be recycled without loss of activity.     

二氧化硅键合丙基哌-N-氨基磺酸作为可回收固体酸催化剂制备2-氨基-3-氰基-4-芳基-5,10-二氧代-5,10-二氢-4H-苯并[g]苯并吡喃和羟基取代的萘-1,4-二酮衍生物FahimeKhorami,HamidRezaShaterian简

An efficient method for the synthesis of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives, using silica-bonded propylpiperazine-N-sulfamic acid as a solid acid, green, heterogeneous catalyst, under ambient and solvent-free conditions, is described. A simple procedure, high yields, short reaction time, safety, and reusability of the catalyst are advantages of these protocols.     

Silica-bonded S-sulfonic acid as a recyclable catalyst for chemoselective synthesis of 1,1-diacetates

A simple and efficient procedure for the preparation of silica-bonded S-sulfonic acid (SBSSA) by reaction of 3-mercaptopropylsilica (MPS) and chlorosulfonic acid in chloroform is described. This solid acid is employed as a recyclable catalyst for the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature.     

Silica-bonded S-sulfonic acid a recyclable catalyst for the synthesis of coumarins

Silica-bonded S-sulfonic acid(SBSSA) was prepared by the reaction of 3-mercaptopropylsilica(MPS) and chlorosulfonic acid in chloroform.This solid acid has been employed as a recyclable catalyst for the synthesis of coumarins from phenols andβ-ketoesters at 80℃under solvent-free conditions.     

Silica-bonded N-propylsulfamic acid as a recyclable catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

2,3-Dihydroquinazolin-4(1H)-one derivatives are synthesized via a one-pot,three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-propylsulfamic acid(SBNPSA) in refluxing ethanol.     

Silica-bonded S-sulfonic acid: an efficient and recyclable solid acid catalyst for the three-component synthesis of α-amino nitriles

Silica-bonded S-sulfonic acid (SBSSA) is employed as a recyclable catalyst for the synthesis of α-amino nitriles. These syntheses were performed via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide under mild reaction conditions at room temperature.     

A green one-pot multicomponent synthesis of 4H-pyrans and polysubstituted aniline derivatives of biological, pharmacological, and optical applications using silica nanoparticles as reusable catalyst

A one-pot practical, efficient, and environmentally benign multicomponent synthesis of 4H-pyrans and polysubstituted aniline derivatives of biological, pharmacological, and optical applications has been developed using a very mild, neutral, and reusable silica nanoparticles as catalyst. The 4H-pyran derivatives were synthesized by a three component reaction of an aldehyde, malononitrile, and 5,5-dimethyl-1,3-cyclohexanedione or ethyl acetoacetate at room temperature or refluxing in ethanol. Alternatively, polysubstituted anilines were synthesized via a four component reaction of an aldehyde, a ketone, and two equivalents of malononitrile in ethanol.     

One-pot synthesis of polyfunctionalized 4H-pyran derivatives bearing fluorochloro pyridyl moiety

Polyfunctionalized 4H-pyran derivatives bearing fluorochloro pyridyl moiety were readily prepared in high yields via one-pot multicomponent reaction catalyzed by piperidine. This present protocol provides an efficient synthetic route to the target compounds with the characteristics of short reaction time, high yield, and easy separation of the products.     

Silica-bonded S-sulfonic acid: an efficient and recyclable solid acid catalyst for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols)

Silica-bonded S-sulfonic acid (SBSSA) is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4′-alkylmethylene-bis(3-methyl-5-pyrazolones) in 75-90% yields.     

Silica-bonded N-propyl sulfamic acid as an efficient recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones under heterogeneous conditions

Silica-bonded N-propyl sulfamic acid(SBNPSA) catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihydropyrimidin-2-(1H)-ones and thiones in environment friendly procedure is described. The facile reaction conditions, simple isolation and purification procedures of this method make it a good option for the synthesis of dihydropyrimidinones.