Schiff bases represent a valuable class of organic compounds, synthesized via condensation of primary amines with ketones or aldehydes. They are renowned for possessing innumerable applications in agricultural chemistry, organic synthesis, chemical and biological sensing, coating, polymer and resin industries, catalysis, coordination chemistry, and drug designing. Schiff bases contain imine or azomethine (-C=N-) functional groups which are important pharmacophores for the design and synthesis of lead bioactive compounds. In medicinal chemistry, Schiff bases have attracted immense attention due to their diverse biological activities. This review aims to encompass the recent developments on the antimicrobial activities of Schiff bases. The article summarizes the antibacterial, antifungal, antiviral, antimalarial, and antileishmanial activities of Schiff bases reported since 2011.
The catalytic application of Cu(INA)2-MOF in click and Biginelli reactions was investigated and a comparative study with the [Cu(INA)2(H2O)4] complex was performed.
Herein, we describe a simple and efficient route to access aniline-derived diselenides and evaluate their antioxidant/GPx-mimetic properties. The diselenides were obtained in good yields via ipso-substitution/reduction from the readily available 2-nitroaromatic halides (Cl, Br, I). These diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide. DFT analysis demonstrated that the electronic properties of the substituents determine the charge delocalization and the partial charge on selenium, which correlate with the catalytic performances. The amino group concurs in the stabilization of the selenolate intermediate through a hydrogen bond with the selenium.
Herein we describe the high yield synthesis of a highly crystalline cobalt(II) MOF with a novel zwitterionic ligand made up of 3,3′,4,4′-BPTC and 1,4-cyclohexanediamine, obtained in situ during the hydrothermal synthesis. The compound with the molecular formula C46H38N4O14Co·2H2O has a molecular mass of 965.7783 g mol−1, a triclinic crystalline system (a = 5.86 Å, b = 9.28 Å, c = 19.92 Å, α = 83.93°, β = 88.01°, γ = 78.59), it is thermally stable up to 300 °C and presents structural stability before and after removing the solvent molecules from its pores. This novel material showed catalytic properties in an electrophilic substitution reaction of indoles and aldehydes allowing the syntheses of bis(indolyl)methanes in high yields under mild reaction conditions and can be reused at least once with the same catalytic activity.
The 1,2,3-triazoles are an important class of organic compounds that are found in a variety of biologically active compounds. The most usual and efficient methodology to synthetize these compounds is the Copper-catalyzed Azide–Alkyne Cycloaddition (CuAAC), preferably by use of click chemistry principles. Therefore, the development of simple, robust, easily accessible and efficient materials as catalysts for this kind of reaction is highly desirable. In this sense, layered hydroxide salts (LHS) emerge as an interesting alternative for the click reaction. Thus, we describe herein the preparation and characterization of copper (II) layered hydroxide salts and their application as catalysts for the CuAAC reaction under solvent-free conditions. This synthetic methodology of CuAAC reaction is attractive as it follows several concepts of green chemistry, such as being easy to perform, allowing purification without chromatographic column, the process forming no sub-products, affording the desired 1,2,3-traizoles in the specific 1,4-disubstituted position in high yield, and having a short reaction time. Moreover, the photocatalysis for the degradation of methyl orange was also highly efficient using the same catalyst.