Solventless triarylmethane synthesis via hydroxyalkylation of anisole with benzaldehyde by modified heteropoly acid on mesocellular foam silica (MCF)

Heteropolyacid Ionic Liquid-Based MCF: An Efficient Heterogeneous Catalyst for Oxidative Desulfurization of Fuel

A new type of catalyst was synthesized by immobilizing heteropolyacid on ionic liquid-modified mesostructured cellular silica foam (denoted as MCF) and applied to the oxidative desulfurization of fuel. The surface morphology and structure of the catalyst were characterized by XRD, TEM, N₂ adsorption-desorption, FT-IR, EDS and XPS analysis. The catalyst exhibited good stability and desulfurization for various sulfur-containing compounds in oxidative desulfurization. Heteropolyacid ionic liquid-based MCF solved the shortage of the amount of ionic liquid and difficult separation in the process of oxidative desulfurization. Meanwhile, MCF had a special three-dimensional structure that was not only highly conducive to mass transfer but also greatly increased catalytic active sites and significantly improved catalytic efficiency. Accordingly, the prepared catalyst of 1-butyl-3-methyl imidazolium phosphomolybdic acid-based MCF (denoted as [BMIM]₃PMo₁₂O₄₀-based MCF) exhibited high desulfurization activity in an oxidative desulfurization system. The removal of dibenzothiophene could achieve levels of 100% in 90 min. Additionally, four sulfur-containing compounds could be removed completely under mild conditions. Due to the stability of the structure, sulfur removal efficiency still reached 99.8% after the catalyst was recycled six times.

Pluronic F127-assisted partial decomposition of ammonium phosphomolybdate and its application as an efficient and recyclable catalyst for the alkylation of toluene with benzyl alcohol

The thermal decomposition of ammonium phosphomolybdate was adjusted by F127 to obtain an efficient and recyclable catalyst for liquid-phase alkylation.

C-4 benzofuranylation of pyrazolones by a metal-free catalyzed indirect heteroarylation strategy

A metal-free catalyzed indirect heteroarylation of pyrazolones with 2-(3-hydroxy-3,3-diarylprop-1-yn-1-yl) phenols has been developed, and a series of novel 4-benzofuranyl substituted pyrazolone derivatives were obtained in moderate to excellent yields (up to 90%). The process has the salient features of metal-free catalysis, operational simplicity, good substrate compatibility and mild reaction conditions. In particular, the integration of the pyrazolone skeleton and benzofuran scaffold into a single molecule is expected to be of potential interest for medicinal research. In addition, the yield and efficiency are basically maintained in the gram-scale experiment, which makes the practical application of the process more prominent.

Metal- and solvent-free synthesis of aniline- and phenol-based triarylmethanes via Brönsted acidic ionic liquid catalyzed Friedel-Crafts reaction

A beneficial, scalable and efficient methodology for the synthesis of aniline-based triarylmethanes has been established through the double Friedel-Crafts reaction of commercial aldehydes and primary, secondary or tertiary anilines using Brönsted acidic ionic liquid as a powerful catalyst, namely [bsmim][NTf₂]. This protocol was successfully performed under metal- and solvent-free conditions with a broad range of substrates, giving the corresponding aniline-based triarylmethane products in good to excellent yields (up to 99%). In addition, alternative aromatic nucleophiles such as phenols and electron-rich arenes were also studied using this useful approach to achieve a diversity of triarylmethane derivatives in high to excellent yields.

Brönsted acidic ionic liquid catalyzed the synthesis of aniline- and phenol-based triarylmethanes via Friedel-Crafts reaction under metal- and solvent-free conditions.

Silver(i)-catalyzed novel ipso-cycloaddition and retro-Friedel–Crafts reaction of ortho-hydroxyphenyl-substituted para-quinone methides

The Lewis acid AgPF6 was found to catalyze novel [2 + 2] ipso-cycloaddition and retro-Friedel–Crafts reaction of o-hydroxyphenyl-substituted p-quinone methides in the presence of H2O, affording the polysubstituted triarylmethanes in up to 97% yields.

A binary MOF of iron and copper for treating ciprofloxacin-contaminated waste water by an integrated technique of adsorption and photocatalytic degradation

A novel MIL 53(Fe–Cu) was synthesized by a solvothermal process. This binary metal organic framework removed ciprofloxacin from waste water.

Comparison in thermal stability and catalytic performance of H4PMo11VO40 heteropolyacid supported on mesoporous and macroporous silica materials

Ordered mesoporous silica, SBA-15 and MCM-41, and three-dimensionally ordered macroporous SiO2 were used as the supports of H4PMo11VO40 heteropolyacid for methacrolein oxidation. The dispersion and structural evolutions of the heteropolyacid along with thermal treatment were investigated. It was found that the heteropolyacid entered the one-dimensional mesoporous channels of SBA-15 and MCM-41, and the crystallization and growth were limited, leading to high dispersion of the heteropolyacid. However, the thermal stability was decreased under high dispersion. The migration of the heteropolyacid was observed to the end of the one-dimensional channels of SBA-15 and the outer surface of MCM-41 with calcination, accompanied by the decomposition of the heteropolyacid and the formation of MoO3. In comparison, the crystallization and growth of heteropolyacid were not limited in the open macropores of three-dimensionally ordered macroporous SiO2. Dispersed particles on the surface of the macropores with size of about 5 nm exhibited a higher thermal stability. The decomposition of the heteropolyacid in the SBA-15 and MCM-41 supported catalysts resulted in the loss of strong acid sites, causing low selectivity to methacrylic acid in methacrolein oxidation. High thermal stability with high exposure of the active sites in the three-dimensionally ordered macroporous SiO2 supported catalyst contributed to the enhancement in the catalytic performance.