A novel magnetic layered double hydroxide as potent mesoporous recyclable heterogeneous nanocatalyst for the synthesis of 1H‐chromeno[2,3‐b]pyridine‐3‐carbonitrile derivatives

Abstract

A magnetically separable cobalt complex of macrocyclic pseudo-crown ether (PCE) immobilized on magnetic Cu/Al-layered double hydroxide (γ-Fe 2 O 3 @Cu 3 Al-layered double hydroxide (LDH)/PCE-Co) was readily fabricated using a simple four-step postsynthetic modification strategy. This newly prepared nanocomposite was characterized by different chemo-physical approaches, including Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), nitrogen adsorptiondesorption isotherms, energy-dispersive X-ray spectroscopy (EDX), and elemental mapping. The catalytic performance of these nanoparticles (NPs) was explored in the synthesis of diverse 1H-chromeno[2,3-b]pyridine-3-carbonitrile derivatives via one-pot three-component reactions under green reaction conditions. Environmentally benign reaction conditions, simple separation, high yields of the reactions, versatility, easy magnetic separation, and reusability for several runs without significant loss of catalytic performance are the key advantages that make this protocol an ideal alternative method for the synthesis of chromene derivatives.

γ‐Fe2O3@Cu3Al‐LDH/HEPES a novel heterogeneous amphoteric catalyst for synthesis of annulated pyrazolo[3,4‐d]pyrimidines

“…The red curve shows the characteristic peaks of γ‐Fe 2 O 3 @Cu 3 Al‐LDH/HMDI whose peaks at 3327, 2932–2856, 2264, 1621, 1571, and 1357 cm −1 are attributed to N‐H, aliphatic C‐H, N═ C═O, C═N and C═O and carbonate CO 2 groups respectively, confirming the successful immobilization of HMDI linker. [ 41,61,62 ] Regarding the FT‐IR spectra of γ‐Fe 2 O 3 @Cu 3 Al‐LDH/HEPES MNPS, the emergence of N═C═O implies the successful attachment of HEPES on the surface by the nucleophilic attacks of OH in HEPES to the N═C═O groups. Finally, the appearance of a new absorption band at the ranges of 1171–1234, 1022–1086, and 627–874 cm −1 is attributed to the O–S–O and S\O stretching modes, confirming the presence of the sulfonic acid functional group.…”

Hercynite silica sulfuric acid: a novel inorganic sulfurous solid acid catalyst for one-pot cascade organic transformations

“…In this sense, magnetic nanoparticles that can be easily separated from the reaction medium using an external magnetic field, appear as the magic solution to this complex problem. 17–21 Over the last few years, magnetic cores as well as their coating surfaces have been dramatically improved and widely used for different purposes. 22–24…”

“…In this sense, magnetic nanoparticles that can be easily separated from the reaction medium using an external magnetic eld, appear as the magic solution to this complex problem. [17][18][19][20][21] Over the last few years, magnetic cores as well as their coating surfaces have been dramatically improved and widely used for different purposes. [22][23][24] In recent years, iron aluminate spinel hercynite (FeAl 2 O 4 ) has attracted interesting attention as a novel nanomagnetic catalytic support for the heterogenization of homogeneous catalytic species due to many advantages such as high adsorption capacities, large surface area, low cost, heterogeneous nature, paramagnetic nature and excellent physicochemical stability.…”

Ni(ii) immobilized on poly(guanidine–triazine–sulfonamide) (PGTSA/Ni): a mesoporous nanocatalyst for synthesis of imines

“…Nowadays, scientists endeavor to rene materials facilitating sustainable development. [17][18][19][20] Mesoporous nanoarchitectures have been the subject of intense research regarding their extraordinary features. [21][22][23] These nanostructures have found a wide range of applications in synthesizing catalysts, 24 functional devices 25 of these structures facilitates the reaction rate by permitting the passage of guest species to the available reaction points.…”