Rapid four-component synthesis of dihydropyrano[2,3-c]pyrazoles using nano-eggshell/Ti(IV) as a highly compatible natural based catalyst

Nano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.

BF3.SiO2 Nanoparticles: A Solid Phase Acidic Catalyst for Efficient One-pot Hantzsch Synthesis of 1,4-dihydropyridines

The solvent-free Hantzsch reaction between ethyl acetoacetate or 1,3-indandione, an aromatic aldehyde and ammonium acetate catalysed by BF3.SiO2 nanoparticles provided an efficient one-step synthesis of 1,4-dihydropyridines in excellent yields.

KAl(SO4)2.12H2O as an Eco-Friendly and Reusable Catalyst for the Synthesis of Amides by the Ritter Reaction

KAl(SO4)2.12H2O (Alum) is an eco-friendly, inexpensive, readily available and reusable and was applied as catalyst to the synthesis of N-alkyl amides from nitriles and alcohols by the Ritter reaction. This solvent-free procedure is very simple with excellent yields and easy work-up.

ZnO Nanoparticles Solid Phase Acidic Catalyst for One-Pot Synthesis of Octahydroquinazolinone Derivatives

The reaction between dimedone, an aromatic aldehyde and urea catalysed by ZnO nanoparticles (ZnO NPs) in refluxing ethanol as a solvent provided a simple and efficient one-pot route for the synthesis of octahydroquinazolinone derivatives in excellent yields.

Monolayer-Protected Silver Nanoparticles: An Efficient and Versatile Reagent for the Synthesis of 3,4-Dihydropyrimidine-2-(1H)-Ones (Thiones)

Silver nanoparticles has been prepared and shown to efficiently catalyse the one-pot, three-component reaction of an aromatic aldehyde, urea or thiourea and a 1,3-diketone at reflux, to afford the corresponding 3,4-dihydropyrimidine-2-(1H)-ones in high yield.

ZnO Nanoparticles: Efficient and Versatile Reagents for Synthesis of 1,4-disubstituted 1,2,3-triazoles

Reaction between azides and acetylenes catalysed by ZnO nanoparticles (ZnO NPs) in solvent EtOH at room temperature provide a simple and efficient one-pot route for the synthesis of 1,4-disubstituted 1,2,3-triazoles in excellent yields. 1,2,3-Triazoles are used in various agricultural, industrial and medical fields.

Nanoparticle Silica Supported Sulfuric Acid (NPs SiO2-H2SO4): A Solid Phase Acidic Catalyst for the One-Pot Synthesis of Benzo[a]Xanthene-11-One Derivatives

The reaction between aromatic aldehydes, dimedone (5,5-dimethyl-1,3-cyclohexane dione) and 2-naphthol catalysed by nanoparticle silica supported sulfuric acid (NPs SiO2-H2SO4) in CH2Cl2 as a solvent at room temperature provided a simple and efficient one-pot route for the synthesis of benzo[a]xanthene-11-one derivatives in high yield. Benzoxanthenes are important heterocycles because of their antiviral, anti-inflammatory and antibacterial activities.

Synthesis of Nanoparticles Silica Supported Sulfuric Acid

Nanostructured SiO2–H2SO)4 has been prepared and shown to efficiently catalyse the one-pot, three-component reaction of an aromatic aldehyde, malononitrile and a cyclic 1,3-diketone at reflux, to afford the corresponding 4 H-chromene derivative in high yield. 4 H-Chromene derivatives are important pharmacological agents exhibiting spasmolytic, diuretic, anticoagulant, anticancer, and antianaphylactic activities.