Fabrication of nitrogen‐enriched graphene oxide/Cu NPs as a highly efficient and recyclable heterogeneous nanocatalyst for the Chan–Lam cross‐coupling reaction

Abstract

Herein, we demonstrate the direct polymerization of melamine and cyanuric chloride in the surface of graphene oxide (GO) (N‐enriched GO) in order to develop a new nanocatalyst. The supramolecular polymerized GO acts not only as a spacer to prevent the restacking of graphene sheets but also as a nitrogen source to generate active centers for Cu NP attachments. Subsequently, the nitrogen on the surface of the GO sheets coordinates with copper ions to generate copper nanoparticles. The prepared nanocatalyst was characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and thermogravimetric analysis. This catalyst showed high efficiency and good activity in the Chan–Lam cross‐coupling reaction of N‐heterocycles and aniline derivatives with high yields in short reaction times. In addition, the nanocatalyst was easily recovered and reused for five consecutive runs without any noticeable loss of performance.

Carbon–nitrogen bond formation using modified graphene oxide derivatives decorated with copper complexes and nanoparticles

“…Nitrogen‐enriched GO decorated with copper NPs (N‐enriched GO/Cu NPs) was investigated for arylation of various amines through Chan–Lam cross‐coupling reaction. [ 59 ] Synthesis of N‐enriched GO was achieved by adding melamine and cyanuric chloride to GO in an ice bath. After stirring for 6 h at room temperature, the mixture was heated for 24 h at 120°C.…”

Cu(OAc)2‐porphyrins as an efficient catalytic system for base‐free, nature mimicking Chan–Lam coupling in water

“…[ 34–40 ] On the other hand, the Chan–Lam coupling enables the preparation of arylamines at mild conditions using highly reactive substrates such as organoboronic acids and amines. [ 41–43 ] Recently, several copper‐based catalytic systems were developed for the Chan–Lam coupling, which include Cu(OAc) 2 /2,2′‐bipyridine/Cs 2 CO 3 , [ 44 ] Cu‐MOF/K 2 CO 3 , [ 45 ] Cu(OAc) 2 /myristic acid/ fac ‐[Ir(ppy) 3 ]/lutidine, [ 46 ] Cu II @montmorillonite K10/K 2 CO 3 , [ 47 ] CuNPs@nitrogen enriched GO, [ 48 ] Cu@Ag‐TiO 2 ‐NGO, [ 49 ] Cu II ‐ N ‐(2‐pyridylmethyl)morpholine‐ N ‐oxide complex, [ 50 ] and Cu(OAc) 2 /2,2′‐bipyridine. [ 51 ] However, these methods associate with certain drawback like the necessity of base, organic solvent, or expensive catalyst.…”

Preparation and characterization of new palladium complex immobilized on (chitosan)/PoPD biopolymer and its catalytic application in Suzuki cross‐coupling reaction

“…[ 15 ] With impregnating or chemically bonded Pd catalyst on the solid support, disadvantages of homogeneous catalyst removed while the Pd features preserved. For this purpose, a wide variety of materials have been used as support, including metal oxides, [ 16,17 ] zeolites, [ 18,19 ] carbon‐based materials, [ 20,21 ] and polymers. [ 22,23 ]…”

“…[15] With impregnating or chemically bonded Pd catalyst on the solid support, disadvantages of homogeneous catalyst removed while the Pd features preserved. For this purpose, a wide variety of materials have been used as support, including metal oxides, [16,17] zeolites, [18,19] carbon-based materials, [20,21] and polymers. [22,23] Natural polymers are of special interest as support for homogeneous catalysts because of their green properties, including nontoxic, biodegradable, and biocompatible materials.…”