Water as a solvent for Ru‐catalyzed click reaction: Highly efficient recyclable catalytic system for triazolocoumarins synthesis

Abstract

A new family of Ru (III) complexes has been synthesized, characterized and their catalytic performance has been tested for alkyne–azide cycloaddition (AAC) in water under ultrasonic irradiation conditions. These complexes are found to be effective heterogeneous catalysts for the regioselective synthesis of 1,4‐disubstituted‐1,2,3‐triazoles giving access to these products in excellent yields. The catalyst system is equally active for one‐pot multi‐component protocol of the AAC reactions. Also, successive sequencing of Huisgen reaction with Knoevenagel condensation reaction results in the effective assembly of a diversified hitherto unreported 1,2,3‐triazolyl coumarin frameworks. In present strategy, the catalyst could be easily isolated by simple filtration and reused up to eight consecutive cycles without significant drop in the reaction yields. During the leaching experiment, there is no leaching amount of the catalyst was detected, suggesting true heterogeneity in the catalytic system. The results of gram‐scale reaction and green metrics calculations also confirmed the sustainability and industrial applicability of the current catalytic protocol.

Design, Sonosynthesis, Quantum‐Chemical Calculations, and Evaluation of New Mono‐ and Bis‐pyridine Dicarbonitriles as Antiproliferative Agents

“…Pyridines are among the most important biochemical scaffolds with broader uses in the medicinal and pharmaceutical industries as well as intermediates in heterocyclic preparations . Among pyridine derivatives, dicyanopyridines act as ‘privileged skeleton’ owing to their prospective uses for therapy . These derivatives were recorded to serve as anti‐prion, human adenosine A2B receptor, antibacterial, anti‐cancer, and anti‐hepatitis B virus .…”

“…Except for non‐polar solvents, polar solvents can combine with US irradiation and thereby create additional heat. More recently, we reported several ultrasonic‐assisted reactions strategies, which allow easy access to the construction of environmentally friendly‐ sustainable synthetic pathways for the preparation of various heterocycles . Computational chemistry, in the few decades, has become important for elucidating structures, mechanisms, molecular properties, and reaction selectivity .…”

Synthesis of Novel Triazole Incorporated Thiazolone Motifs Having Promising Antityrosinase Activity through Green Nanocatalyst CuI‐Fe3O4@SiO2 (TMS‐EDTA)

“…The Fe 3 O 4 @SiO 2 (TMS‐EDTA) nanoparticle was prepared according to the literature. [ 72–76 ] Afterward, the resulting Fe 3 O 4 @SiO 2 (TMS‐EDTA) nanoparticle was dispersed in copper (ΙΙ) sulfate solution (1 M, 25 ml in deionized water) and stirred at 60 °C for 15 hr. The resulting hybrid was separated with a magnet and washed successively with water (3 × 10 mL) and finally dried in vacuum at room temperature to give the CuI supported‐Fe 3 O 4 @SiO 2 (TMS‐EDTA) nanoparticles.…”

Recent Progress in Catalytic Synthesis of 1,2,3-Triazoles

“…Finally, the authors proposed a mechanism in which Ru catalyzes the cycloaddition of azide and alkyne to give 4-substituted-1H-1,2,3-triazole (compound A, Scheme 9) that subsequently give an in situ substitution reaction with the benzyl bromide to afford the N-benzylated-products 24 (Scheme 9). Recently, Arafa and Nayl developed a new interesting method for the regioselective synthesis of 1,4-DTs in water by using a new family of Ru complexes [44]. The main drawbacks related to the employment of ruthenium for azide-alkyne cycloaddition (AAC) reactions, such as long reaction time, limited scopes, thermal activation, were overcome in this protocol, exploiting ultrasonic irradiation as alternative energy sources.…”