New In Situ Catalysts Based on Nitro Functional Pyrazole Derivatives and Copper (II) Salts for Promoting Oxidation of Catechol to o-Quinone

Abstract

Herein, new substituted ligands based on pyrazole (L1–L4) were synthesized via a one-step by condensing (1H-pyrazole-1-yl) methanol with different primary amine compounds. The present work utilized the catalytic properties of the in situ complexes formed by these ligands with various copper (II) salts viz. Cu(CH3COO)2, CuSO4, CuCl2, and Cu(NO3)2 for the oxidation of catechol to o-quinone. The studies showed that the catalytic activities depend on the nature and concentration of the ligand, the nature of the counterion, and the solvent. It was observed that the complex formed by L2 and Cu(CH3COO)2 exhibited good catalytic activity in methanol with Vmax of 41.67 µmol L−1 min−1 and Km of 0.02 mol L−1.

New Catalysts Based on Carboxylate Sn(IV) Complexes Used in the Oxidation Reaction of 3,5-Di-Tert-Butylcatechol to 3,5- Di-Tert-Butyl-O-Benzoquinone

“…In the literature, we noted studies concerning the synthesis of biomimetic oxidation catalysts to reproduce catecholase activity [24][25][26][27][28][29][30]. Most of the results described use catalysts with the aim of mimicking the metallic active site environment of the catecholase enzyme and also understanding the catalytic properties for activating molecular oxygen.…”

Crystal structure and Hirshfeld surface analysis of bis(3-aminopyrazole-κN 1)bis(3-aminopyrazole-κN 2)bis(nitrato-κO)copper(II)

“…In addition, numerous examples of practical applications have been offered for pyrazole-containing coordination compounds. For example, copper(II) complexes with pyrazole-containing ligands have been shown to exhibit catalytic (Gamez et al, 2001;Titi et al, 2023), antibacterial (Zaimovic ´et al, 2022), antifungal (Titi et al, 2023) and antitumor (Ruan et al, 2012) activities.…”

New catalysts based on carboxylate Sn(IV) complexes used in the oxidation reaction of 3,5-di-tert-butylcatechol to 3,5-di-tert-butyl-o-benzoquinone

“…In the literature, we noted studies concerning the synthesis of biomimetic oxidation catalysts to reproduce catecholase activity [24][25][26][27][28][29][30]. Most of the results described use catalysts with the aim of mimicking the metallic active site environment of the catecholase enzyme and also understanding the catalytic properties for activating molecular oxygen.…”