A facile and efficient synthesis of highly functionalized pyrroles via a four-component one-pot reaction in the presence of Ni(II) Schiff base/SBA-15 heterogeneous catalyst

Abstract

In this study, the Ni(II) Schiff base/SBA-15 catalyst was successfully synthesized and characterized by employing FT-IR, XRD, TGA, EDX, ICP-OES, TEM, and SEM analysis. In addition, BJH and BET techniques were used to determine the specific surface area, pore size, and pore volume of the catalyst, which were 538 m2 g−1, 6 nm, and 1.01 cm3 g−1, correspondingly. Under favorable conditions, we have designed a one-pot multicomponent reaction combining aromatic amines, aldehydes, nitroalkanes, and 1,3-dicarbonyl compounds in conjunction with the presence of the Ni(II) Schiff base/SBA-15 as a heterogeneous catalyst to synthesize a range of functionalized pyrroles in reasonable to excellent yields an admirable yield percentage (94%), a short reaction time of approximately 8 h, mild reaction conditions of 70 °C, a wide range of substrates, the possibility of large-scale synthesis, low cost, and the avoidance of hazardous reagents and solvents. In addition, this method can synthesize more desirable pyrroles by adding or altering numerous functional groups to the reactants in a one-pot process. Specifically, a Hammett plot variant was employed to evaluate the reaction effectively.