Ugi-modified nano NaY zeolite for the synthesis of new 1,5-dihydro-2H-pyrrol-2-ones under mild conditions

In this study, it was aimed to modify the nano zeolite surface via a multi-component reaction to obtain high functionality in one pot process. For this purpose, the Ugi-reaction was applied for the first time to develop a novel hydrogen-bonding nanocatalyst. The nano NaY zeolite was post-modified using 3-aminopropyltriethoxysilane (APTES), followed by the Ugi reaction with salicylaldehyde, tert-butyl isocyanide, and acetic acid to create carboxamide-functionalized nano NaY. The presence of hydroxyl groups, pores, and carboxamide moieties on the surface of nano zeolite could improve the reactivity, dispersibility, and hydrogen bonding formation capability of the nano zeolite. The formation of the nanocatalyst was investigated by Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), Differential Thermal Analysis (DTA), Fourier Transform Infrared spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), Scanning Electron Micrograph (SEM), Elemental analyses, and Energy Dispersive Spectroscopy (EDS). The catalytic activity of the synthesized modified nano zeolite was examined in the three component-reaction of aldehydes, amines, and ethyl pyruvate to obtain new pyrrol derivatives in high yields under mild conditions. After separation by filtration, the catalyst can be recycled for up to seven subsequent runs without any appreciable activity loss. Thus, the titled heterocycles can be prepared in an eco-friendly manner since the catalyst is easily recovered and reused, and the procedure is simple to perform. The results indicated that the catalytic system developed in this study may be useful for the preparation of other beneficial heterocyclic compounds under environmentally benign conditions.

Automated summary

In this study, a multi-component reaction was used to modify the surface of nano zeolite, resulting in high functionality. The Ugi reaction was applied for the first time to develop a hydrogen-bonding nanocatalyst by post-modifying nano NaY zeolite with 3-aminopropyltriethoxysilane (APTES) and then reacting it with salicylaldehyde, tert-butyl isocyanide, and acetic acid. The modified nano zeolite showed improved reactivity, dispersibility, and hydrogen bonding formation capability. The nanocatalyst was characterized using various techniques and exhibited excellent catalytic activity in a three-component reaction. The catalyst could be easily separated and reused multiple times without significant activity loss, making this eco-friendly method suitable for the preparation of other important heterocyclic compounds.