# GO/MNPs–TEA–CuI in water: a green and efficient catalytic system for multicomponent preparation of highly substituted imidazoles and oxazoles

## TL;DR

A green and efficient catalyst system is developed for making imidazoles and oxazoles in water, offering a sustainable method for chemical synthesis.

## Contribution

The novel contribution is the development of a GO/MNPs–TEA–CuI catalyst system for multicomponent synthesis of heterocycles in aqueous media.

## Key findings

- The catalyst achieves excellent yields (77%–99%) for imidazoles and oxazoles in short reaction times.
- The system is magnetically recoverable and reusable without significant loss of efficiency.
- It tolerates diverse functional groups and enables versatile substrate design.

## Abstract

A sustainable and highly efficient catalytic protocol has been developed employing graphene oxide-supported magnetic nanoparticles functionalized with triethanolamine and copper(I) iodide (GO/MNPs–TEA–CuI) for the synthesis of functionalized imidazole and oxazole derivatives. This magnetically recoverable catalyst promotes multicomponent coupling reactions between aryl aldehydes, aryl nitriles, and terminal alkynes in aqueous media under reflux conditions, emphasizing its environmentally benign nature. The system efficiently affords a broad scope of products in excellent yields (77%–99%) within short reaction times (15–80 min for imidazoles and 1–8 h for oxazoles). The catalyst exhibits outstanding activity, attributed to the synergistic interaction between the GO surface, magnetic core, and Cu(I) active centers, resulting in high TON and TOF values. Moreover, it tolerates diverse functional groups, including electron-donating, electron-withdrawing, and heteroaromatic substituents, enabling versatility in substrate design. The catalyst can be conveniently separated using an external magnet and reused for several consecutive cycles without appreciable loss of efficiency. Overall, this green and recyclable catalytic system offers an economical and scalable approach for constructing nitrogen- and oxygen-containing heterocycles, providing a promising route for sustainable synthesis in pharmaceutical and fine chemical industries.

Flowchart depicting a chemical reaction process using GO/MNPs-TEA-CuI as a catalyst. Includes reaction conditions with water under reflux and displays two pathways: one with Ar-CHO, NH₄OAc leading to benzimidazole formation, yielding 85-99% across 16 examples; the second with Ar-CN forming an aryl ether, yielding 77-98% across 16 examples. Ar groups are identified as phenyl, naphthyl, pyridine, thiophene, and furan. The chart highlights advantages like green and sustainable approach, high efficiency, reusability, broad substrate compatibility, structural stability, and one-pot synthesis.