Preparation and Application of CuO@RHA/MCM-41 Nanocomposite for the Synthesis of Fused pyrano[4,3-b]chromenones

An Fe3O4 supported O-phenylenediamine based tetraaza Schiff base-Cu(ii) complex as a novel nanomagnetic catalytic system for synthesis of pyrano[2,3-c]pyrazoles

In this research, we present a post-synthetic method for synthesizing a novel nanomagnetic Cu(II) Schiff base complex and investigate its efficiency in catalytic organic conversion reactions. Various spectroscopic analyses were employed to characterize the physiochemical characteristics of the resulting nanocomposite. The experimental results successfully demonstrate the catalytic application of the prepared Cu-complex in the preparation of pyrano[2,3-c]pyrazole heterocycles. This synthesis involved a one-pot three-component condensation reaction, wherein hydrazine hydrate, ethyl acetoacetate, malononitrile, and aromatic aldehydes were combined under reflux conditions using water as the solvent. Notably, the heterogenized complex exhibited exceptional catalytic performance, achieving remarkable conversion rates and selectivity, all accomplished using only 12 mg of the catalyst. Furthermore, thorough stability assessments of this catalyst were conducted through reusability and hot filtration tests, which confirmed its non-leaching properties and demonstrated excellent results over the course of five consecutive runs.