Microwave-promoted efficient conversion of acetophenones to 1,3,5-triarylbenzenes catalyzed by H3PW12O40 and nano-silica supported H3PW12O40 as reusable catalysts

Sandwich type polyoxometalates encapsulated into the mesoporous material: synthesis, characterization and catalytic application in the selective oxidation of sulfides

The A-type sandwich polyoxometalates of [(HOSn^IVOH)₃(PW₉O₃₄)₂]¹²⁻ (P₂W₁₈Sn₃) and [(OCe^IVO)₃(PW₉O₃₄)₂]¹²⁻ (P₂W₁₈Ce₃) were immobilized for the first time into the porous metal–organic framework MIL-101(Cr). FT-IR, powder X-ray diffraction, SEM-EDX, ICP analysis, N₂ adsorption and thermogravimetric analysis collectively confirmed immobilization and good distribution of polyoxometalates into cages of MIL-101(Cr). The catalytic activities of the homogeneous P₂W₁₈Sn₃ and P₂W₁₈Ce₃ and the corresponding heterogeneous catalysts were examined in the oxidation of sulfides to sulfones with H₂O₂ as the oxidant at room temperature. The effects of different dosages of polyoxometalates, type of solvent, reaction time, amount of catalyst and oxidant in this catalytic system were investigated. The new P₂W₁₈Sn₃@MIL-101 and P₂W₁₈Ce₃@MIL-101 nanocomposites exhibited good recyclability and reusability in at least five consecutive reaction cycles without significant loss of activity or selectivity.

The A-type sandwich POMs of [(HOSn^IVOH)₃(PW₉O₃₄)₂]^12– (P₂W₁₈Sn₃) and [(OCe^IVO)₃(PW₉O₃₄)₂]^12– (P₂W₁₈Ce₃) were immobilized for the first time into the porous MIL-101 MOF. Their catalytic activities were examined in the oxidation of sulfides to sulfones at room temperature.

Environmentally friendly cyclotrimerization of substituted acetophenones catalyzed by a new nanocomposite of γ-Al2O3 nanoparticles decorated with H5PW10V2O40

An efficient protocol for the synthesis of C₃-symmetrical 1,3,5-triarylbenzenes under solvent-free conditions. γ-Al₂O₃/H₅PW₁₀V₂O₄₀ nanocomposite is introduced as a highly reusable catalyst.

A new method for the preparation of 1,3,5-triarylbenzenes catalyzed by nanoclinoptilolite/HDTMA

An efficient method for the preparation of 1,3,5-triarylbenzenes. Natural surface-modified NCP as a new and reusable catalyst. Using solvent-free conditions.

H6P2W18O62/Nanoclinoptilolite as an efficient nanohybrid catalyst in the cyclotrimerization of aryl methyl ketones under solvent-free conditions

A new natural nanohybrid material HPA/NCP was prepared. An efficient and environmentally benign method for cyclotrimerization of acetophenones is reported. Water was the only by-product.

New pyridinium-based ionic liquid as an excellent solvent-catalyst system for the one-pot three-component synthesis of 2,3-disubstituted quinolines

The synthesis of a variety of 2,3-disubstituted quinolines has been achieved successfully via a one-pot three-component reaction of arylamines, arylaldehydes and aliphatic aldehydes in the presence of butylpyridinium tetrachloroindate(III), [bpy][InCl4], ionic liquid as a green catalyst and solvent. Mild conditions with excellent conversions, and simple product isolation procedure are noteworthy advantages of this method. The recyclability of the ionic liquid makes this protocol environmentally benign.

A highly efficient and recyclable molybdate sulfuric acid (MSA) catalyst for the synthesis of dimethyl (2,3-dihydro-1H-inden-6-ylamino) (substituted) methylphosphonates under microwave irradiation

The attractive features of this methodology are simple procedure, green reaction, reusability and high efficiency of the catalyst and easy workability.