Mesostructured vanadia–alumina catalysts for the synthesis of vitamin K3

Super-magnetization of Co-pectin/gelatin biocomposite for selective synthesis vitamin K3: Design, fabrication and revealing role of the stabilizers

High pollution and low productivity of the traditional method for synthesis of vitamin group K require an efficient, low-cost, and environmentally sustainable biocatalyst as a greener process. These have encouraged us to design and fabricate a series of novel Co NPs impregnated pectin-gelatin (Co@PTNC, Co@GTNC & Co@PT_0.7GT_0.3NC) and grafted pectin-gelatin modified magnetic beads (Co@MPT_0.7GT_0.3NC) by the in situ reduction-precipitation procedure and chemical application in the selective synthesis of vitamin K3 without any promoters or ligands. The chemical structure and morphological properties were fully characterized. Additionally, the influence of structural parameters (i.e., kind of stabilizer with different ratio (n_PT/n_GT), amount of Co loading, durability, size, distribution, and Leaching test) and operating parameters (i.e., reaction time, reaction temperature, nature of the solvent, and concentration of oxidant) on the efficacy of the biocatalysts was evaluated in detail. The green synthesis involves several advantages, like the heterogeneous nature of catalysts, environmentally-friendly and mild conditions, high recovery efficiency due to superparamagnetism, high activity, and the sustainable performance of the biocatalyst.

VAlPOs as Efficient Catalysts for Glycerol Conversion to Methanol

The catalytic activity of a series of vanadium aluminophosphates catalysts prepared by sol-gel method followed by combustion of the obtained gel was evaluated in glycerol conversion towards methanol. The materials were characterized by several techniques such as X-ray diffraction (XRD), UV-vis, Fourier-transform infrared (FTIR), Raman and X-ray photoelectron (XPS) spectroscopies. The amount of vanadium incorporated in aluminophosphates framework played an important role in the catalytic activity, while in the products distribution the key role is played by the vanadium oxidation state on the surface. The sample that contains a large amount of V4+ has the highest selectivity towards methanol. On the sample with the lowest vanadium loading the oxidation path to dihydroxyacetone is predominant. The catalyst with higher content of tetrahedral isolated vanadium species, such V5APO, is less active in breaking the C–C bonds in the glycerol molecule than the one containing polymeric species.

Synthesis and characterization of a novel ruthenium(ii) trisbipyridine complex magnetic nanocomposite for the selective oxidation of phenols

Anchoring ruthenium(ii) trisbipyridine complex [Ru(Bpy)₃]²⁺ into a magnetic dendritic fibrous silica nanostructure produces an unprecedented strong nanocatalyst, FeNi₃/DFNS/[Ru(Bpy)₃]²⁺.

Synthesis of Fe3O4@SiO2@OSi(CH2)3NHRN(CH2PPh2)2PdCl2 type nanocomposite complexes: Highly efficient and magnetically-recoverable catalysts in vitamin K3 synthesis

The synthesis of aminomethylphosphine-metal complexes have opened a new perspective to the catalytic applications of organic compounds. Magnetic Fe3O4 nano-core was synthesized using the closed quartz tube with Teflon cover and microwaved 200°C for 1h with power controlled instrument set to max. 600W. Novel nano-composite supported; Fe3O4@SiO2(CH2)3NHArN(CH2PPh2)2 and Fe3O4@SiO2(CH2)3N(CH2PPh2)2 type bis(diphenylphosphinomethyl)amino ligands and their Pd(II) complexes have been synthesized and characterized with FT-IR, SEM, EDX, TEM, UV-Visible, XRD and TG/DTA techniques. All the complexes were used as heterogeneous catalysts in the oxidation of 2-methyl naphthalene (2MN) to 2-methyl-1, 4-naphthoquinone (vitamin K3, menadione, 2MNQ) in the presence of hydrogen peroxide and acetic acid. Selectivity reached about 55-60% with a conversion of 90-96% using the nano-magnetite supported aminomethylphosphine-Pd(II) complexes. The complexes were very active in three times in the catalytic recycling experiments in five catalytic cycles.