Novel Heterogeneous Catalyst For Synthesis Research Articles

Post-synthetic generation of nanomagnetized tetraaza-copper (II): as a novel heterogeneous catalyst for synthesis of fused N-heterocycles

Post-synthetic generation of nanomagnetized tetraaza-copper (II): as a novel heterogeneous catalyst for synthesis of fused N-heterocycles

L-arginine modified graphene oxide: A novel heterogeneous catalyst for synthesis of benzo[b]pyrans and pyrano[3,2‑c]chromenes

L-arginine modified graphene oxide (GO-Arg) was introduced as a new heterogeneous biocatalyst for synthesis of benzo[b]pyran and pyrano[3,2‑c]chromene derivatives. First GO was synthesized and then, Arg was covalently bonded on its surface. The new catalyst was analyzed using spectroscopic techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS) and Raman. XRD analysis results showed that, Arg was located between the graphene oxide layers. Comparison of the bond intensity ratio of the D and G (ID/IG) in GO and GO-Arg confirmed the presence of Arg via covalent bond on the GO surface. XPS analysis also confirmed the successful modification through the presence of CN bonds in the structure. Moreover, changes in morphology of the samples were observed using SEM analyze, respectively. Evaluation of the performance of the catalyst in the synthesis of benzo[b]pyran and pyrano[3,2‑c]chromene derivatives showed presentable results. Using of amino acid as an available organocatalyst, its stabilization by a simple method on graphene oxide, reusing the catalyst up to 5 times, and introducing a highly pure product are positive points of this work.

CoFe2O4/Cu(OH)2 magnetic nanocomposite: an efficient and reusable heterogeneous catalyst for one-pot synthesis of β-hydroxy-1,4-disubstituted-1,2,3-triazoles from epoxides

A magnetically separable CoFe2O4/Cu(OH)2 nanocomposite was prepared and characterized by various techniques such as FESEM, EDS, TEM, XRD, VSM and FT-IR. This novel composite was used as a heterogeneous catalyst for the regioselective synthesis of β-hydroxy-1,4-disubstituted-1,2,3-triazoles from sodium azide, terminal alkynes and structurally different epoxides in water at 60 °C. The formation of the product proceeds in one pot through a mechanism that involves an in situ generated organic azide intermediate, followed by rapid ring closure with the alkyne component. The simple procedure, short reaction times, perfect regioselectivity, high product yields, and use of a benign solvent and nontoxic catalyst are among the considerable advantages of this protocol. Furthermore, the catalyst was easily separated using an external magnet and reused several times without any significant loss of catalytic activity or magnetic properties.

Mesoporous ZnS nanospheres: a high activity heterogeneous catalyst for synthesis of 5-substituted 1H-tetrazoles from nitriles and sodium azide

Mesoporous ZnS nanospheres is a novel heterogeneous catalyst for synthesis of 5-substituted 1H-tetrazoles from various nitriles and sodium azide with excellent catalytic performance.