A Novel Fe(III) Complex of Bispicen Ligand Covalently Attached to an Fe3O4 Nanomagnet: Catalytic Properties in C‐H Oxidation and Benzoxazol Synthesis

ABSTRACT This study discusses the development of an effective and environmentally friendly C‐H oxidation process for the creation of oxygenated compounds in the presence of tert ‐butyl hydroperoxide by a magnetically recoverable Fe 3 O 4 @SiO 2 ‐FeL Bpn nanocomposite. L Bpn stands for a deprotonated, pyridine‐based, four‐dentate, bispicen ligand. The synthesised catalyst was characterised by Fourier‐transform infrared spectroscopy (FTIR), energy‐dispersive X‐ray analysis (EDX), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Fe 3 O 4 @SiO 2 ‐FeL Bpn (40 mg) was introduced as a catalyst in the presence of TBHP (4 eq) for the oxidation of varied C–H bonds to the related carbonyl compounds in high yields. Fe 3 O 4 @SiO 2 ‐FeL Bpn (5 mg) was used for the synthesis of benzoxazole derivatives from 1 mmol of every substrate of aldehydes, ammonium acetate, and catechol. By this process, vast amounts of benzoxazoles were satisfyingly obtained in the presence of Fe 3 O 4 @SiO 2 ‐FeL Bpn in H 2 O under moderated situations, and whole products were gained with excellent results. Fe 3 O 4 @SiO 2 ‐FeL Bpn was recovered from the reaction environment through a simple exterior magnet and reused for three times without any remarkable reactivity loss. Moreover, a hot filtration test confirmed the heterogeneous character of the catalyst.