Fe 3 O 4 @BNPs‐CPTMS‐Chitosan‐Pd(0) as an Efficient and Stable Heterogeneous Magnetic Nanocatalyst for the Chemoselective Oxidation of Alcohols and Homoselective Synthesis of 5‐Subestituted 1 H ‐Tetrazoles

In this content, a stable, efficient, active, reusable and inexpensive magnetic boehmite was synthesized by hydrothermal sol‐gel method. In the next step magnetic boehmite immobilized further with palladium chitosan complex (Fe 3 O 4 @BNPs‐CPTMS‐Chitosan‐Pd(0)). This novel nanocatalyst was used for the oxidation of alcohols in ethanol and the preparation of 5‐substituted tetrazoles in solvent‐free conditions. To confirm the structure of catalyst, a variety of techniques, including FT‐IR, XRD, FESEM, TEM, EDX, mapping, VSM, TGA‐DTA, BET, ICP and UV‐Visible were used. The mol % of catalyst was obtained with ICP (2.8 mol%). Also, some benefits of the catalyst are: excellent magnetic properties, easy separating from the reaction mixture with the external magnet, the use of cheap and affordable materials, good surface area (55.94 m 2 /g), low palladium leaching from the catalyst surface, use the green ligand and the use of catalyst for at least 5 consecutive times without reducing the catalytic activity.