NCNT-Catalyzed Knoevenagel Condensation

Significance

Nitrogen-containing carbon nanotubes (NCNT) were used as solid base catalysts for Knoevenagel condensation. The NCNT materials were prepared by chemical vapour deposition of C- and N-containing precursors (acetonitrile or pyridine) over a SiO₂-supported Co or Ni catalyst (C. N. R. Rao and co-workers Chem. Phys. Lett. 2000, 322, 333-340; C. Tang et al. Carbon 2004, 42, 2625-2633). The Knoevenagel condensation of benzaldehyde and ethylcyanoacetate was performed with NCNT in EtOH under reflux conditions to give ethyl-α-cya­nocinnamate in 50% yield. The recovered ­catalyst was reused without loss of catalytic ­activity.