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This study presents the development of a novel organo-inorganic hybrid material (zeolite-SO3H) through the three-component reaction of carbon disulfide and 1,3-propane sultone with aminopropyl-functionalized NaY zeolite. The formation of the zeolite-SO3H catalyst was investigated using SEM, TEM, TGA, EDS, XRD, FT-IR, DLS, and elemental analyses. The described zeolite-SO3H was used as a Brønsted acid nanocatalyst for the one-pot four-component synthesis of functionalized 1,4-dihydropyridine derivatives, and one-pot three-component synthesis of pyridine derivatives under mild conditions. The synthesized acidic nanocatalyst offers several advantages, including easy separation, high product yields, short reaction times, high recyclability, and reusability. Using centrifugation to separate the catalyst, it can be recycled up to seven times without losing significant activity. [ABSTRACT FROM AUTHOR]

An efficient acid‐catalyzed synthesis of 1,5‐diaryl‐3‐(arylamino)‐1H‐pyrrol‐2(5H)‐ones is reported using novel N‐sulfonic acid modified poly (styrene‐diethylenetriamine) through three‐component reaction between aldehyde, amine, and ethyl pyruvate in high yields and short times. This heterogeneous solid catalyst is produced by reacting amine‐modified chloromethyl polystyrene with neat chlorosulfonic acid. The structure of the synthesized catalyst was examined with Fourier transform‐infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron micrograph (SEM), Brunauer–Emmett–Teller (BET), energy dispersive spectroscopy (EDS), and elemental analyses. The heterogeneous catalyst has many advantages, including an easy work‐up procedure, a high product yield, and the capability to be easily regenerated and reused for at least five cycles without losing its activity. [ABSTRACT FROM AUTHOR]

A series of structurally diverse spiro 1,3-oxazines were conveniently prepared from three-component reaction of conjugated imines, dialkyl acetylenedicarboxylates (DAAD), and N,N'-disubstituted parabanic acids in dry dichloromethane without catalyst. Initially, various conjugated imines were synthesized from reaction of aniline derivatives with cinnamaldehyde. Subsequently, reaction of conjugated imines with DAAD and N,N'-substituted parabanic acids led to mixture of the corresponding spirocyclic 1,3-oxazines in high yields. The obtained diastereoisomers of the spirocyclic 1,3-oxazines were isolated and characterized by FT-IR, 1H, 13C NMR spectral data, elemental analyses and mass spectrometry. [ABSTRACT FROM AUTHOR]

A new solid acid catalyst, consisting of 12‐phosphotungstic heteropoly acid (HPW) supported on graphene oxide/silica nanocomposite (GO@SiO2), has been developed via immobilizing HPW onto an amine‐functionalized GO/SiO2 surface through coordination interaction (GO@SiO2‐HPW). The GO@SiO2‐HPW nanocomposite was characterized by Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and powder X‐ray diffraction (XRD). The prepared nanocomposite could be dispersed homogeneously in water and further used as a heterogeneous, reusable, and efficient catalyst for the synthesis of benzimidazoles and benzothiazoles by the reaction of 1,2‐phenelynediamine or 2‐aminothiophenol with different aldehydes. [ABSTRACT FROM AUTHOR]