Natural asphalt oxide-grafted carboxylic acid: a sustainable heterogeneous catalyst for synthesis of pyrano[2,3-<i>c</i>]pyrazoles and 2-amino-3-cyanopyridines in water.

ABSTRACT: In this study, we successfully utilized natural asphalt as a natural carbon substrate for the synthesis of a novel heterogeneous Brønsted acid nanocatalyst, Re-NA-CH₂CO₂H. The -COOH functional groups present on the surface of Reduced Natural Asphalt Oxide (Re-NA-oxide) serve as catalytic sites for Brønsted acid. This arrangement, in addition to increasing acidity, also expands the surface area accessible for catalytic activity, positioning Re-NA-oxide as a viable option for a range of acid-catalyzed reactions. The synthesized catalyst was characterized using various methods, including FT-IR, TGA, SEM, EDX and TEM. This catalyst was employed in the synthesis of pyrano[2,3-c]pyrazole and 2-amino-3-cyanopyridine derivatives through four-component reactions involvi

SUBMITTER: Rashidi S 

PROVIDER: S-EPMC12265887 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature