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

SiO2–OSO3H Nanoparticles: An Efficient, Versatile and New Reagent for the One-Pot Synthesis of 2-Amino-8-Oxo-4,8-Dihydropyrano[3,2-b]Pyran-3-Carbonitrile Derivatives in Water, a Green Protocol

In a one-pot three-component reaction, an aromatic or aliphatic aldehyde, malononitrile and 5-hydroxy-2-hydroxymethyl-4H-pyran-4-one were condensed for the synthesis of 2-amino-8-oxo-4,8-dihydropyrano[3,2- b]pyran-3-carbonitrile derivatives in the presence of nano-silica sulfuric acid (SiO2–OSO3H nanoparticles) in improved yields. The catalyst is recoverable by simple filtration and can be used in the subsequent reactions.

Synthesis of Silica Supported Perchloric Acid Nanoparticles (HClO4–SiO2 NPs): Efficient Synthesis of Biscoumarin Derivatives in Water

Reaction between aromatic aldehydes or phenylglyoxals and 4-hydroxycoumarin catalysed by silica supported perchloric acid nanoparticles (HClO4–SiO2 NPs) in water at reflux provided a simple and efficient route for the synthesis of biscoumarin derivatives in high yields.

A Fast, Highly Efficient, and Green Protocol for Synthesis of Biscoumarins Catalyzed by Silica Sulfuric Acid Nanoparticles as a Reusable Catalyst

Silica sulfuric acid nanoparticles have been prepared and shown to efficiently catalyse the reaction between an aromatic aldehyde or phenylglyoxal and a 4-hydroxycoumarin at reflux in EtOH to afford the biscoumarin derivatives in high yield.

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.

A Clean, Simple, and Efficient Synthesis of 2-Substituted Aryl (Indolyl) Kojic Acid Derivatives by Kaolin/Ag Nanocomposite as a Reusable Catalyst: A Green Protocol

Kaolin/Ag nanocomposite (kaolin/Ag nanocomposite) was synthesized in a nanoreactor by the calcination of the precursor at high temperature and was shown to efficiently catalyze the one-pot, three-component reaction of an aromatic aldehyde, kojic acid, and indole derivatives under solvent-free conditions to afford the corresponding 2-substituted aryl (indolyl) kojic acid derivatives in high yield.