Anchoring Cu (II) on Fe3O4@ SiO2/Schiff base: a green, recyclable, and extremely efficient magnetic nanocatalyst for the synthesis of 2-amino-4H-chromene derivatives

ZnO–TiO2 Nanoparticles Coated by the Dioxomolybdenum (VI) bis-Schiff Base Complex for Catalytic Oxidation of Sulfides

“…Observably, the optimum activity for the MoO 2 L 2 catalyst was observed in entry 13 at 40 °C with 51 and 54% for MePhSO and Ph 2 SO, respectively (Table 2a). At the same reaction temperature (40 °C) with prolongation of time (30,60,90,120, and 150 min), the percentage yield of the overoxidation products increased gradually to 6, 15, 17, 35, and 46% for MePhSO 2 and also to 9, 16, 22, 38, and 50% for Ph 2 SO 2 , respectively.…”

“…28 Furthermore, Zamanifar et al fabricated a heterogeneous catalyst of the Mo(VI) Schiff base complexcoated Al-MCM-41 as a highly efficient catalyst for the sulfide oxidation. 29 Generally, the immobilizing or supporting processes of metal−Schiff base complexes on the surface of various metal oxides have been accomplished by cross-linked organic silicates via the substituted alkoxy or hydroxyl groups, e.g., 3aminoalkyltrialkoxysilicate 30,31 or 3-haloalkyltrialkoxysilane. 32 Considerably, such immobilization procedures through silicate cross-linkers could be carried out through complicated and costly synthetic pathways.…”

“…Numerous published articles have highlighted the immobilization of Mo–Schiff base complexes on the surface of various nanomaterials, e.g., TiO 2 , ZnO, Fe 3 O 4 , Fe 3 O 4 –TiO 2 , SiO 2 , and Fe 3 O 4 –SiO 2 ; surprisingly, despite being a naval piece of work, there are no reported attempts at immobilization of Mo–Schiff base complexes on ZnO–TiO 2 nanoparticles. − …”

Immobilized transition metal (II) bis–imine chelate on ZnO@TiO2 nanoparticles as sufficient catalysts for alcohol oxidation and for α,β‐cinnamic acid decarboxylative bromination

“…22 Using 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO), the oxidation of secondary and primary alcohols was optimized catalytically by copper(II)-imine complexes, as reported by Gao et al 23 Moreover, the catalytic behavior of some new synthesized copper(I)-imine complexes was studied by Al-Hunaiti et al in the aerobic alcohol oxidation using an organic oxidant. 24 The current catalytic performance of immobilized Cu(II)-imine complexe on NPs of Fe 3 O 4 was examined by Hadian-Dehkordi et al 25 Considerably, immobilization procedures for the metal-organic frameworks on the nanomaterials' surface of oxides, mixed oxides, and alloys of transition metals were reported with the functionalized crosslinked organo-silicates (organochlorosilanes) of Si OR (alkoxysilicates) or Si OH (hydroxysilicates) chains, such as 3-aminoalkyltrialkoxysilicate 26,27 or 3haloalkyltrialkoxysilane. 28 Indeed, within silicate crosslinkers, the immobilizing processes gained highly expensive and complicated procedures.…”

“…Considerably, immobilization procedures for the metal–organic frameworks on the nanomaterials' surface of oxides, mixed oxides, and alloys of transition metals were reported with the functionalized cross‐linked organo‐silicates (organochlorosilanes) of SiOR (alkoxysilicates) or SiOH (hydroxysilicates) chains, such as 3‐aminoalkyltrialkoxysilicate 26,27 or 3‐haloalkyltrialkoxysilane 28 . Indeed, within silicate cross‐linkers, the immobilizing processes gained highly expensive and complicated procedures 29 .…”