No abstract

No abstract

No abstract

In this work, a new curcumin‐based bidentate linker ligand, CurOAc, including two –COO− moieties at positions‐4 in phenyl rings, was designed, synthesized, and characterized. Accordingly, its corresponding zinc‐organic framework, Zn‐CurOAc, as a bio‐metal–organic framework (MOF) has been prepared and evaluated in the one‐pot three‐component Biginelli condensation reaction of substituted aromatic aldehydes, urea, and dimedone in ethanol. Zn‐CurOAc shows an excellent catalytic performance for the synthesis of tetrahydroquinazolinone derivatives at room temperature with high turnover frequency (TOF) values (5.43–10.86 h−1). The chemical structure of Zn‐CurOAc was characterized by fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP‐OES), field emission‐scanning electron microscopy (FE‐SEM), transmission electron microscope (TEM), energy dispersive X‐ray (EDX), differential thermal analysis (DTA), and thermogravimetric analysis (TGA) techniques. This new catalytic approach was proceeded by the excellent isolated yields, short reaction times, and easy workup.

No abstract

A novel melamine‐based metal‐organic framework (MTsCOO‐Cu) has been designed, synthesized, and structurally characterized by FT‐IR, NMR, PXRD, FE‐SEM, EDX mapping, DTA, and TGA techniques. The MTsCOO‐Cu is successfully synthesized by the reaction of melamine with tosyl chloride and oxidation of methyl groups of the tosyl counterpart to carboxylic acids moieties and a consequent reaction with copper ion under ultrasonic irradiation. The synthesized MTsCOO‐Cu is catalytically used for the facile preparation of a series of 5‐substituted‐1H‐tetrazoles derivatives via click [3+2] cycloaddition reactions between various arrays of aromatic and aliphatic nitriles and sodium azide in PEG‐400 at 75 °C up to 86 %. The crucial reaction parameters including the type of solvent, temperature, and catalyst loading in progressing the reaction are evaluated and discussed. The synthesized MTsCOO‐Cu MOF showed an excellent catalytic activity, high chemical and thermal stabilities above 600 °C, simple preparation with readily available starting materials, and also ease of recyclability and reusability for four consecutive uses without considerable loss of activity. The output of this work may open new approaches for using new generations of MOFs catalysts in diverse chemical transformations.