Single-pot tandem oxidative/C-H modification amidation process using ultrasmall PdNP-encapsulated porous organosilica nanotubes.

Abstract

Herein, we studied a single-pot method with a dual catalysis process towards the conversion of primary aromatic alcohols to amides using ultrasmall PdNPs of controlled uniform size (1.8 nm) inside hybrid mesoporous organosilica nanotubes (MO-NTs). The catalyst exhibited excellent performance in water under mild conditions and showed high stability. The catalytic activity towards the tandem oxidation of alcohols in the presence of amine salts and H2O2 to their corresponding amides without producing byproducts was evaluated, and high yields were obtained for all products. The structure of the organosilica nanotubes containing palladium nanoparticles was investigated using various characterization techniques such as XRD, TEM, BET, solid-state 29Si NMR and solid-state 13C CP MAS NMR. Catalyst recycling tests showed that the catalytic power of PdNPs@B-SNTs was preserved after 8 cycles and a slight decrease in catalyst activity was observed.