An efficient catalytic system based on 7,8-dihydroxy-4-methylcoumarin and copper(II) for the click synthesis of diverse 1,4-disubstituted-1,2,3-triazoles under green conditions

Plant mediated synthesis of flower-like Cu2O microbeads from Artimisia campestris L. extract for the catalyzed synthesis of 1,4-disubstituted 1,2,3-triazole derivatives

This study presents a novel method for synthesizing 1,4-disubstituted 1,2,3-triazole derivatives through a one-pot, multi-component addition reaction using flower-like Cu2O microbeads as a catalyst. The flower-like Cu2O microbeads were synthesized using an aqueous extract of Artimisia Campestris L. This extract demonstrated the capability to reduce and stabilize Cu2O particles during their initial formation, resulting in the formation of a porous flower-like morphology. These Cu2O microbeads exhibit distinctive features, including a cubic close-packed (ccp) crystal structure with an average crystallite size of 22.8 nm, bandgap energy of 2.7 eV and a particle size of 6 µm. Their catalytic activity in synthesizing 1,4-disubstituted 1,2,3-triazole derivatives was investigated through systematic exploration of key parameters such as catalyst quantity (1, 5, 10, 15, 20, and 30 mg/mL), solvent type (dimethylformamide/H2O, ethanol/H2O, dichloromethane/H2O, chloroform, acetone, and dimethyl sulfoxide), and catalyst reusability (four cycles). The Cu2O microbeads significantly increased the product yield from 20% to 85.3%. The green synthesis and outstanding catalytic attributes make these flower-like Cu2O microbeads promising, efficient, and recyclable catalysts for sustainable and effective chemical transformations.

The liquid phase of 4,4'-trimethylenedipiperidine: a safe and greener dual-task agent for clean and facile synthesis of coumarin derivatives

A practical and facile synthesis of various coumarin derivatives was conducted using a liquid phase of 4,4'-trimethylenedipiperidine as a safe and greener dual-task reagent under catalyst-free and solvent-free conditions. This reagent is a commercially available solid and can be handled easily, having a liquid phase over a vast temperature range, high thermal stability, low toxicity, and good solubility in green solvents such as water and ethanol. It is worth mentioning that 4,4'-trimethylenedipiperidine could be completely recovered and regenerated after a simple process. The current method has other merits, including (a) minimizing the use of high-risk and toxic reagents and solvents; (b) the use of a secure and recoverable medium-organocatalyst instead of metal-based catalysts, (c) avoid tedious processes, harsh conditions, and a multi-step process for the preparation of catalysts, (d) transform phenol and salicyladehyde derivatives into the corresponding coumarin derivatives in good to high yields, (e) minimize hazardous waste generation. TMDP could be easily recovered and reused several times with no change in its activity. Furthermore, the current work demonstrated that the liquid phase of 4,4'-trimethylenedipiperidine can be a promising medium in organic reaction at higher temperatures due to its broad liquid range temperature, thermal stability, acceptor/donor hydrogen bond property, and other unique merits. New methodology for the synthesis of coumarines using liquid phase of TMDP under mild conditions.

Supported Cu(II)-Schiff base: novel heterogeneous catalyst with extremely high activity for eco-friendly, one-pot and multi-component C-S bond-forming reaction toward a wide range of thioethers as biologically active cores

An effective and proficient process for the synthesis of a variety of thioethers via the one-step reaction of benzyl halides, aryl halides, and thiourea is presented. This strategy is a one-pot procedure to achieve a variety of thioethers without the requirement to thiols as starting compounds. A range of thioethers containing electron donating/electron-withdrawing functional groups were obtained with good to excellent yields under mild conditions. Moreover, the nanocatalyst exhibited excellent recyclability for the reaction, making it more sustainable. One-pot and multi-component synthesis, high yields of final products, green reaction media, high activity of nanocatalyst, simple separation of the products and catalyst, and high regioselectivity are several highlights of this method.

Facile and direct halogenation of 1,2,3-triazoles promoted by a KX–oxone system under transition metal free conditions

A convenient and efficient oxidative halogenation of 4-aryl 1,2,3-triazoles is realized at ambient temperature under transition metal free conditions.

Solvent-free and room temperature synthesis of 3-arylquinolines from different anilines and styrene oxide in the presence of Al2O3/MeSO3H

A highly efficient, simple and environmentally friendly synthesis of 3-arylquinolines has been developed in the presence of Al₂O₃/MeSO₃H via one-pot reaction of anilines and styrene oxide. This methodology provides very rapid access to 3-arylquinolines in good to excellent yields under solvent-free conditions at room temperature in air.