Sustainable Catalytic Process with a High Eco‐Scale Score for the Synthesis of Five‐, Six‐, and Seven‐Membered Heterocyclic Compounds Using Nanocrystalline Zeolites

Abstract

Nanocrystalline ZSM-5 and Beta zeolites were evaluated as catalysts for the one-pot synthesis of aw ide range of five-, six-, and seven-memberedh eterocyclic compounds. Seven-membered compounds were prepared by the reaction of o-phenylenediamine and ketones, whereas five-membered compounds were obtained when o-aminothiophenol was reactedw ith ketones under the same reactionc ondition. Severalo ther seven-membered compounds werep repared by the reaction of (E)-chalcone with o-phenylenediamine/o-aminothiophenol, whereas the six-membered compounds described in this study were prepared by the reaction of o-phenylenediamine with 2-bromoacetophenone/2hydroxy acetophenone. Twoo ther five-membered compounds were prepared by the reactiono fa niline with ben-zaldehyde and thioglycolic acid, and the reaction of glycerol with acetone. The mechanisms responsible for the formation of the different products were elucidated based on the results of time-dependent 1 HNMR experiments.T ot he best of our knowledge, this work represents the first reported systematicassessment of the catalytic activity of nanocrystalline zeolites for the synthesis of heterocyclic compounds. Notably,t he catalysts were readily recovered and reused without any considerable decrease in their catalytic activity.T he high eco-scale score and low E-factorv alue of this process clearly demonstrate that it represents ag reen and sustainable synthetic route for the preparation of aw ide range of heterocyclic compoundso fs ignificant industrial importance.Scheme1.Some representative examples of biologically important molecules containingf ive-, six-, and seven-membered heterocyclicunits.Scheme2.Various pathways for the construction of five-membered heterocyclic compoundsreported in the literature.

Stimulating the Visible-Light Catalytic Activity of Bi2MoO6 Nanoplates by Embedding Carbon Dots for the Efficient Oxidation, Cascade Reaction, and Photoelectrochemical O2 Evolution

“…Heterocyclic compounds are prepared using hazardous synthesis process. Recently we showed that five-, six-, and seven-member heterocyclic compounds can be prepared by o -aminothiophenol and o -phenylenediamine using nanocrystalline zeolites . In the present study, five-membered benzimidazole and benzothiazole were prepared by highly eco-friendly synthesis process.…”

Octahedral MnO2 Molecular Sieve-Decorated Meso-ZSM-5 Catalyst for Eco-Friendly Synthesis of Pyrazoles and Carbamates

“…E-factor can be represented as the mass ratio of waste generated to the desired product. The eco-score is calculated based on the reported procedure described in our previous study . Eco-score and E-factor are calculated for some of the reactions investigated in this study and provided in Tables S6 and S7.…”

“…Catalysis and industrial researchers are making significant efforts to develop catalysts and reagents in order to improve the efficiency of such single-step processes . The 21st century is currently witnessing consistent development of environmentally friendly synthesis processes (with high Eco Score and E-factor) to get the desired products in high yield . An exponential growth in the synthesis and use of heterogeneous catalysts is taking place all over the world .…”

“…Synthesis of heterocyclic compounds and amine derivatives are important with respect to the pharmaceutical industry. Recently, we reported a sustainable synthetic strategy for the preparation of a wide range of heterocyclic compounds using nanocrystalline zeolites . Most of these syntheses are based on acid–base catalysts.…”

Recent Developments on Catalyst‐Free, Visible‐Light‐Triggered Synthesis of Heterocyclic Scaffolds and Their Mechanistic Study

“…Ghosh et al reported a highly efficient, rapid and environment-benign protocol for the synthesis of Hantzsch 1,4dihydropyridine (18) under visible light irradiation via a onepot three-component reaction of aldehydes (15), ethyl acetoacetate ( 16) and ammonium hydroxide (17) in aqueous ethanol with excellent yields (92 %) (Scheme 9). [32] According to the suggested mechanism, a radical anion 10 A was formed by an electron transfer from ammonia (17) to the carbonyl group of ethyl acetoacetate (16) in the presence of light.…”