Supported palladium oxide nanoparticles in Al-SBA-15 as an efficient and reusable catalyst for the synthesis of pyranopyrazole and benzylpyrazolyl coumarin derivatives via multicomponent reactions

An eco-friendly method for diversity-oriented synthesis of substituted dihydropyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin derivatives has been achieved via one-pot and multicomponent reaction in the presence of PdO/Al-SBA-15 as an efficient and recyclable catalyst in H₂O/EtOH under reflux conditions. The significant merits of this method are wide scope, high yields of the desired products, short reaction times and simple workup procedure. In addition, this nanocatalyst was simply recovered and reused five times without significant loss in catalytic activity and also performance.

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Supported Palladium Oxide Nanoparticles in SBA‐15 as a Heterogeneous Catalyst for the Aerobic Oxidation of Alcohols

Palladium nanoparticles were first synthesized through the thermal decomposition method and subsequently immobilized on ordered mesoporous silica material, SBA‐15, to afford PdO/SBA‐15 catalyst. The synthesized catalyst was characterized by X‐ray diffraction, nitrogen adsorption‐desorption measurement, transmission electron microscopy, and inductively coupled plasma atomic emission spectrometry. The catalytic activity was tested for the aerobic oxidation of alcohols. Easy recovery, high yeilds and relatively short reaction times were observed for the mentioned catalyst.     

An iron Schiff base complex loaded mesoporous silica nanoreactor as a catalyst for the synthesis of pyrazine-based heterocycles

An iron Schiff base complex was encapsulated in SBA-15 mesoporous silica to afford a Fe(III)-Schiff base/SBA-15 heterogeneous nanocatalyst for the synthesis of pyridopyrazine and quinoxaline heterocycles. These reactions proceeded in water with excellent yields. The catalyst was characterized by physico-chemical and spectroscopic methods and found to retain the characteristic channel structures of the SBA-15, allowing good accessibility of the encapsulated metal complex.