a simple and facile method for the preparation offe2+ supported on hydroxyapatite-core-shell-γ-fe2o3 nanoparticles (γ-fe2o3@hap-fe2+ nps) as an environmentally friendly and recyclable green catalyst is described and used for the one-pot synthesis of benzimidazoles and benzoxazole derivatives via reactions between aromatic aldehydes and ortho‐phenylenediamine or ortho‐aminophenol in aqueous medi...

In this study, multi component Hantzsch reaction was carried out between various  Aromatic Aldehyde with Dimedone,Ethyl acetateand ammonium acetate to produce polyhydroquinolinederivatives under solvent-free conditions at 110oC by a (Zinc oxide  nanocatalyst) as effective Lewis acid. The remarkable advantages offered by this method compared with other methods are a green catalyst, simple work-u...

One potential Lewis acid that has received negligible attention as a catalyst is the carbocation. Here we show the potential of triaryl methylium ions as highly powerful Lewis acid catalysts for organic reactions. The Lewis acidity of the triaryl methylium ion can be easily tuned by variation of the electronic properties of the aromatic rings and the catalytic activity of the carbocation is sho...

While Lewis acids andmetal amides are among themost frequently usedmetal species, they are believed to be incompatible when combined. Here we describe a Lewis acid/metal amide hybrid, which contains electron-withdrawing groups and basic and bulky nitrogen functional groups in the same metal complex, as a novel catalyst. We have synthesized In(N(SiMe3)2)2Cl (In(HMDS)2Cl) and In(HMDS)2OTf as Lewi...

In general, Lewis acid catalysts are metal-based compounds that owe their reactivity to a low-lying empty orbital. However, one potential Lewis acid that has received negligible attention as a catalyst is the carbocation. We have demonstrated the potential of the carbocation as a highly powerful Lewis acid catalyst for organic reactions. The stable and easily available triphenylmethyl (trityl) ...

New types of Lewis acids as water-stable catalysts have been developed. Metal salts such as rare earth metal triflates can be used in carbon–carbon bond-forming reactions in aqueous media. These salts can be recovered after the reactions and reused. Furthermore, Lewis acid–surfactant-combined catalysts, which can be used for reactions in water without using any organic solvents, have been also ...