Pd@BCN nanostructures catalyzed chemoselective synthesis of benzimidazoles via one-pot reductive cyclization of o-nitroanilines with aldehydes

Abstract

In the present study, a rapid one-pot synthetic protocol has been developed for the preparation of benzimidazole derivatives through BCN-supported palladium nanoparticle (Pd@BCN)-catalyzed reductive cyclization of o-nitroanilines with aromatic aldehydes. The developed methodology exhibited excellent functional group tolerance toward electron-donating, electron-withdrawing, halogenated, heteroaromatic, and fluorinated aldehydes, producing the corresponding benzimidazole derivatives in good yields. The present catalytic system offers several advantages including short reaction time, low catalyst loading, recyclability, operational simplicity, mild reaction conditions, and excellent yields. In further, control experiments revealed the synergistic role of the BCN support and palladium nanoparticles in enhancing the catalytic activity.