Solvent and bio-degradable catalyst for the construction of fully-substituted benzenes

Abstract

An economical and efficient green chemical method is developed for the synthesis of multi-functionalized benzene derivatives through a natural biopolymer Cellulose Sulfuric Acid (CSA) as a heterogeneous catalytic sequence of Knoevenagal/Michael/Cyclization under solvent-free conditions at 70 o C. The metal-free catalytic system under solvent-free condition processes the reactions with a good efficiency. This protocol should be amenable advantages such as simple workup and recoverability of the biopolymer catalyst and reusing several times without significant decrease in catalytic activity.

An effective process for the synthesis of dihydropyridines via SO4−2/SnO2‐catalyzed Hantzsch reaction

“…In extension to our earlier effort towards finding new methods for construction of biologically active small heterocyclic molecules, STO was used as a recyclable solid catalyst. [ 38,39 ] Keeping these features in mind, we initially developed a model reaction of acetoacetanilide, ammonium hydroxide, and different aldehydes in the presence of STO (Scheme 1).…”

A New and an Eco‐Friendly Approach for the Construction of Multi‐Functionalized Benzenes with Computational Studies

“…Water is a universal green solvent, [15–18] non‐flammable, [19] safe, cheap, most abundant, [20] and non‐toxic [21] . Solvent‐free and water as a solvent encourage C−C new bond formation during the cyclization process, [22–26] decreases the activation energy of reactants, [21] and accelerate product yield in the transition state through the hydrophobic effect and hydrogen bonding enhancement [19,27] . Furthermore, reactions carried out in aqueous media show remarkable selectivity and reactivity which are not found in organic media [28] …”

Ce−ZSM‐5: A Highly Capable Catalyst for the Construction of Acridines in Water and Their Computational Study against DNA Gyrase Protein

“…Research has shifted towards developing more environmentally friendly procedures because of the necessity to enhance chemical practices using green methodologies to reduce their harmful effects on health and the environment [1,2] . In organic synthesis, green chemistry seeks to reduce the environmental destruction caused by toxic materials and waste production [3,4] . Many organic reactions using water as a solvent have been reported as they offer several environmental and economic benefits [5,6] .…”