We describe the synthesis of a novel Fe 3 O 4 /amidoxime (AO)/Pd nanocatalyst by grafting of AO groups on Fe 3 O 4 nanoparticles and subsequent deposition of Pd nanoparticles. Prior to grafting of AO, the 2-cyanoethyl-functionalized Fe 3 O 4 nanoparticles prepared through combining 2-cyanoethyltriethoxysilane and Fe 3 O 4 were treated with hydroxylamine. The AO-grafted Fe 3 O 4 nanoparticles were then used as a platform for the deposition of Pd nanoparticles. The catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopies, vibrating sample magnetometry, wavelength-and energy-dispersive X-ray spectroscopies and inductively coupled plasma analysis. Fe 3 O 4 /AO/Pd is novel phosphine-free recyclable heterogeneous catalyst for Sonogashira reactions. Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device and recycled seven times without any significant loss in activity.Fe 3 O 4 /AO/Pd as an effective nano catalyst in the sonogashira reaction

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A hybrid material of palladium supported on diaminoglyoxime-functionalized Fe 3 O 4 was used as an effective and recyclable catalyst in Mizoroki-Heck coupling reactions. The catalyst was very effective for the Mizoroki-Heck reaction of aryl halides with styrene and conversion was in most cases excellent. The yields of the products were in the range 75-98%. The catalyst showed good stability and could be recovered and reused for six reaction cycles without significant leaching and loss its catalytic activity.

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Phenyl sulfonic acid functionalized mesoporous SBA-15 silica (SBA-15-Ph-SO 3 H) was prepared through the silanization of activated mesoporous SBA-15 with diphenyldichlorosilane (DPCS) followed by silylation and sulfonation, and characterized by XRD, FT-IR, nitrogen adsorption analyses, BET theory and TEM. The sulfonic acid groups anchored to the silica surface of the pore walls were resistant to leaching in organic and aqueous solutions under mild conditions. This catalyst was found to be a recyclable heterogeneous catalyst for the rapid and efficient synthesis of various 2H-indazolo[2,1-b]phthalazine-triones and triazolo [1,2-a]indazole-triones. Also, this silylated mesoporous material containing phenylsulfonic acid groups has a greater stability of the sulfonic acid surface toward water than that of silica sulfuric acid (SSA) and sulfonated SBA-15.Scheme 3 Proposed mechanism for the SBA-15-Ph-SO 3 H-catalyzed synthesis of indazolo[2,1-b]phthalazine-triones. Fig. 5 The catalytic activity of SBA-15-Ph-SO 3 H for five cycles of the reaction of 3-nitrobenzaldehyde, dimedone and phthalhydrazide.This journal is