Solvent-free Conditions In Excellent Yields Research Articles

Application of Nanomagnetic Metal-Organic Frameworks in the Green Synthesis of Nicotinonitriles via Cooperative Vinylogous Anomeric-Based Oxidation.

In the current study, we synthesized a new nanomagnetic metal-organic framework Fe3O4@MIL-53(Al)-N(CH2PO3)2 and characterized it using various techniques. This nanomagnetic metal-organic framework was used for the synthesis of a wide range of nicotinonitrile derivatives as suitable drug candidates by a four-component reaction of 3-oxo-3-phenylpropanenitrile or 3-(4-chlorophenyl)-3-oxopropanenitrile, ammonium acetate (NH4OAc), acetophenone derivatives, and various aldehydes including those bearing electron-donating, electron-withdrawing, and halogen groups, which afforded desired products (27 samples) via a cooperative vinylogous anomeric-based oxidation (CVABO) mechanism under solvent-free conditions in excellent yields (68-90%) and short reaction times (40-60 min). Increasing the surface-to-volume ratio, easy separation of the catalyst using an external magnet, and high chemical and temperature stability are the advantages of the described nanomagnetic metal-organic frameworks.

Sulfonic Acid-Functionalized Magnetic Nanoparticles as an Efficient Catalyst for the Synthesis of Benzo[4, 5]imidazo[1, 2-a]pyrimidine Derivatives, 2-Aminobenzothia Zolomethylnaphthols and 1-Amidoalkyl-2-naphthols.

Carbon-based sulfonated catalysts have several advantages but their separation by filtration is still a challenge. On the other hand, the synthesis of magnetic sulfonated carbon nanoparticle indicated that the magnetic separation could be an efficient way to separate the catalyst from the reaction mixture. In order to synthesize a separable magnetic Fe3O4@C-SO3H nanoparticle (MNPs) with high catalytic activity in organic transformation, three environmental-benign and low-cost sulfonic acidfunctionalized magnetic nanoparticle (Fe3O4@C-SO3H) were successfully synthesized. The Nano catalysts were prepared by solvothermal carbonization of Sucrose (Suc), Starch (Sta) or Cellulose (Cel) in the presence of Fe3O4 Nanoparticle and then grafting of the sulfonic groups on the surface of resulted Fe3O4@C nanoparticles in the presence of p-Toluenesulfonic. Then the Nano catalysts were characterized using XRD, FESEM and FT-IR. Three Fe3O4@C-SO3H were successfully synthesized. The resulted MNPs were used for the synthesis of benzo [4, 5] imidazo[1, 2-a]-pyrimidine derivatives, 2/-aminobenzothiazolomethylnaphthols and 1-amidoalkyl-2-naphthols under solvent-free conditions in excellent yields. It was found that high catalytic activity and easy magnetic separation from the reaction mixture are important achievement with regard to the efficiency and reusability of the catalyst in synthesis. The MNPs were synthesized and used as an efficient catalysts for the one-pot synthesis of benzo [4, 5] imidazo[1, 2-a]-pyrimidine derivatives, 2/-aminobenzothiazolomethylnaphthols, and 1-amidoalkyl-2- naphthols under solvent-free conditions in excellent yields. High catalytic activity and easy magnetic separation from the reaction mixture are two factors for evaluating the performance of Fe3O4@C-SO3H nanoparticles in the organic transformations.

Vitamin B1 supported on alumina as an efficient heterogeneous catalyst for synthesis of tetrahydro-2,6-dioxopyrimidin-4-yl)-2,3-dihydrophthalazine-1,4-dione derivatives

The efficient synthesis of tetrahydro-2,6-dioxopyrimidin-4-yl)-2,3-dihydrophthalazine-1,4-dione derivatives via four-component reaction of hydrazine hydrate, phthalic anhydride, aromatic aldehydes and barbituric acid using vitamin B1 supported on alumina (VB1-Al2O3) as a heterogeneous catalyst under thermal solvent-free conditions in excellent yields is described.

Magnetic nanoparticles supported imidazolium-based ionic liquids as nanocatalyst in microwave-mediated solvent-free Biginelli reaction

The magnetic Fe3O4 nanoparticles supported imidazolium-based ionic liquids (MNPs–IILs), namely 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium hydrogen sulfate (MNPs–IIL–HSO4), 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium acetate (MNPs–IIL–OAc) and 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium chloride (MNPs–IIL–Cl) were used as efficient new catalysts for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones under microwave irradiation and solvent-free conditions in excellent yields. Utilization of easy reaction conditions, catalyst with high catalytic activity and good reusability, and simple magnetically work-up, makes this green protocol as an interesting option for the economic synthesis of Biginelli compounds. Microwave technology as an eco-friendly green synthetic approach has gradually been used in this organic procedure. Combining the advantages of microwave irradiation and magnetically nanocatalyst, this method provides an efficient and much improved modification of the original Biginelli reaction. We believe that this procedure appears to have a broad scope with respect to variation in the 3,4-dihydropyrimidin-2(1H)-ones (thiones). we have developed a rapid, effective, validated and environmental-friendly method for the synthesis of dihydropyrimidinones (thiones) using Fe3O4 nanoparticles immobilized imidazolium salt catalyst in microwave irradiation and solvent-free conditions. Reduced reaction times, high turnover frequency, high yields of products, absence of solvent and recyclability of catalyst make our catalyst a valuable system addition to previously reported methods. This green methodology should be amenable to construct new substituted dihydropyrimidinones scaffolds with potential biological applications.

MoO3 Nanoparticles Synthesis via Hydro-Solvothermal Technique and Its Application as Catalyst for Efficient Ring Opening of Epoxides With Amines Under Solvent-Free Conditions

Molybdenum trioxide nanoparticles were synthesized using ammonium heptamolybdate tetrahydrate (AHM) through a facile hydro-solvothermal technique. The materials were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The mean diameter of semispherical α-MoO3 nanoparticles was determined to be 20 ± 5 nm. The catalytic performance of obtained products was examined in the ring opening of epoxides with diverse amines under solvent-free conditions in excellent yields and short period of times.

Facile one-pot synthesis of chromeno[4,3-b]quinoline derivatives catalyzed by Cu(II)-Schiff base/SBA-15

Abstract A novel, one-pot, simple, environmentally benign and efficient protocol has been employed for the synthesis of chromeno[4,3-b]quinoline derivatives in the presence of catalytic amounts of Cu(II)-Schiff base/SBA-15 under solvent-free conditions in excellent yields and rates.

ChemInform Abstract: Solvent‐Free Catalytic Preparation of 2,6‐Dibenzylidenecycloalkanones Using 2‐Hydroxyethylammonium Acetate Ionic Liquid as Catalyst.

Various 2,6-dibenzylidenecycloalkanones were readily prepared in a condensation reaction catalyzed by 2-hydroxyethylammonium acetate ionic liquid under solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times, lack of solvent, simplicity of performance, and low cost.

A Facile One-pot Synthesis and Heterocyclisation of (R)-2-amino-3-((aroylcarbamothioyl)thio)propanoic Acids

A series of ( R)-2-amino-3-((aroylcarbamothioyl)thio)propanoic acid derivatives have been synthesised by a one-pot, three-component reaction of L-cysteine with ammonium thiocyanate in the presence of various acid chlorides under solvent-free conditions in excellent yields. These compounds were converted to ( R)-2-thioxothiazolidine-4-carboxylic acid in water under reflux conditions.

Solvent-free catalytic preparation of 2,6-dibenzylidenecycloalkanones using 2-hydroxyethylammonium acetate ionic liquid as catalyst

Various 2,6-dibenzylidenecycloalkanones were readily prepared in a condensation reaction catalyzed by 2-hydroxyethylammonium acetate ionic liquid under solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times, lack of solvent, simplicity of performance, and low cost.

MnO2–MWCNT nanocomposites as efficient catalyst in the synthesis of Biginelli-type compounds under microwave radiation

A novel Biginelli-like cyclocondensation reaction is efficiently catalyzed by MnO2–CNT nanocomposites as a new catalyst under microwave irradiation and solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times and solvent-free reaction conditions, reducing reaction steps and purification of products by non-chromatographic methods. The activity, recovery and reusability of the catalyst are found to be good.

Nanocrystalline MgAl2O4 as an efficient catalyst for one-pot synthesis of multisubstituted imidazoles under solvent-free conditions

An efficient and eco-friendly procedure has been developed using nanocrystalline MgAl2O4 with specific surface area as catalyst for rapid and an improved synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions in excellent yields. The method has several benefits, such as shorter reaction time, recyclable catalyst and excellent yields.

Mild basic ionic liquids catalyzed new four-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones

A new four-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives using three weak basic ionic liquids such as 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium acetate, pyrrolidinium formate, and pyrrolidinium acetate as efficient catalysts for condensation reaction of hydrazine monohydrate, phthalic anhydride, malononitrile or ethyl cyanoacetate, and aromatic aldehydes under ambient and solvent-free conditions in excellent yields is described.

InCl3‐Driven Regioselective Synthesis of Functionalized/Annulated Quinolines: Scope and Limitations

The efficient, regioselective synthesis of functionalized/annulated quinolines was achieved by the coupling of 2-aminoaryl ketones with alkynes/active methylenes/α-oxoketene dithioacetals promoted by InCl(3) in refluxing acetonitrile as well as under solvent-free conditions in excellent yields. This transformation presumably proceeded through the hydroamination-hydroarylation of alkynes, and the Friedländer annulation of active methylene compounds and α-oxoketene dithioacetals with 2-aminoarylketones. In addition, simple reductive and oxidative cyclization of 2-nitrobenzaldehyde and 2-aminobenzylalcohol, respectively, afforded substituted quinolines. Systematic optimization of the reaction parameters allowed us to identify two-component coupling (2CC) conditions that were tolerant of a wide range of functional groups, thereby providing densely functionalized/annulated quinolines. This approach tolerates the synthesis of various bioactive quinoline frameworks from the same 2-aminoarylketones under mild conditions, thus making this strategy highly useful in diversity-oriented synthesis (DOS). The scope and limitations of the alkyne-, activated methylene-, and α-oxoketene dithioacetal components on the reaction were also investigated.

Synthesis of highly substituted imidazoles using Brønsted acidic ionic liquid, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate, as teusable catalyst

Bronsted acidic ionic liquid, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate, has been used as an efficient and reusable catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under solvent-free conditions in excellent yields.

An environmental friendly approach for the synthesis of highly substituted imidazoles using Brønsted acidic ionic liquid, N-methyl-2-pyrrolidonium hydrogen sulfate, as reusable catalyst

Brønsted acidic ionic liquid, N-methyl-2-pyrrolidonium hydrogen sulfate, has been used as an efficient and reusable catalyst for the one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles under thermal solvent-free conditions in excellent yields.

Nano Fe 3O 4 as magnetically recyclable catalyst for the synthesis of α-aminophosphonates in solvent-free conditions

The three component, one-pot synthesis of α-aminophosphonates has been achieved using super magnetic nano iron oxide at 50 °C under solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times, magnetically recyclable catalyst, and solvent-free reaction conditions.

A mild and efficient chemoselective N-benzyloxycarbonylation of amines using TBAB as a catalyst under solvent-free conditions

We describe a mild and efficient method for the chemoselective N-benzyloxycarbonylation of amines by treatment of amines and aminoesters with benzyloxycarbonyl chloride (Cbz-Cl) in the presence of TBAB under solvent-free conditions in excellent yields. The method is general for the preparation of a wide variety of N-Cbz derivatives of aliphatic, aromatic amines, and aminoesters.

One-pot, three-component route to 2 H-indazolo[2,1- b]phthalazine-triones

2 H-Indazolo[2,1- b]phthalazine-1,6,11(13 H)-trione derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of phthalhydrazide, dimedone, and aromatic aldehydes under solvent-free conditions in excellent yields and short reaction times.

A Mild and Efficient Chemoselective Protection of Primary Alcohols as Pivaloyl Esters Using La(NO3)3·6H2O as a Catalyst under Solvent-free Conditions

Abstract Primary alcohols are selectively and efficiently protected as their pivaloyl esters with pivaloyl chloride in the presence of catalytic amounts of La(NO3)3·6H2O at room temperature under solvent-free conditions in excellent yields.

Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the three-component synthesis of α-amino nitriles

α-Amino nitriles are synthesized by the three-component coupling reaction of aldehydes, amines and trimethylsilyl cyanide using sulfamic acid as a heterogeneous solid acid catalyst, under solvent-free conditions in excellent yields. The catalyst was recovered by simple filtration and was recycled in subsequent reactions.