Reusable silica-bonded S-sulfonic acid catalyst for three-component synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes and 2-amino-4H-pyrans in aqueous ethanol

Preparation and characterization of theh-BN/Fe3O4/APTES-AMF/CuIInanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles

“…[48][49][50] Moreover, these heterocyclic scaffolds also serve as photoactive materials and building blocks of natural products. 51,52 In consideration of the substantial importance of these bioactive motifs, a variety of catalysts including silica, 53 metal oxide nanoparticles, 54 Cu(II) oxymetasilicate, 55 Ca-MCM, 56 and silica bonded S-sulfonic acid 57 have been reported so far. However, most of the approaches have encountered serious shortcomings, such as prolonged reaction time, harsh reaction conditions, use of expensive catalysts, toxic solvents, strong acidic conditions, tedious separation processes, and low product yields.…”

Fe3O4@L‐lysine‐Pd(0) organic–inorganic hybrid: As a novel heterogeneous magnetic nanocatalyst for chemo and homoselective [2 + 3] cycloaddition synthesis of 5‐substituted 1H‐tetrazoles

“…[13][14][15] The close correlations between the specificity of biological activity and the structure of complex molecule have provided the impetus to develop a molecular hybridization strategy to access challenging target molecules with privileged substructures inherent in bioactive molecules. [12,16,17] N-containing heterocycles are very interesting and elegant synthetic targets and incorporated in a number of medicinally important natural products and syntheticz pharmaceuticals. [18,19] Moreover, the synthetic pharmaceuticals with interesting biological activities such as antimicrobial and antitumor inhibitors include N-containing tetrazole structural system in their structures.…”

γ-Alumina Catalyzed Green Synthesis of Pyran’s Annulated Heterocyclic Systems via Three-Component Reaction

“…In addition, some of them have been used as the anti-malarial, anti-fungal, analgesics and herbicidal agents (Davoll et al 1972;Levitt 1982). Thus, development of new greener approaches for their synthesis is still of interest (Sarrafi et al 2012;Kidwai et al 2012;Baghbanian et al 2013;Aswin et al 2014).…”