Sulfonic acid-functionalized nano zeolite NaY: a Brønsted acid catalyst for the green synthesis of pyridines and 1,4-dihydropyridines†

Abstract

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.