Facile and efficient reductive N-alkylation of nitrobenzenes with alcohols catalyzed by Cu–Cr/γ-Al2O3

A facile and efficient method for reductive N-alkylation of nitrobenzenes with alcohols catalyzed by the bimetallic catalyst Cu30Cr5/γ-Al2O3, in a fixed-bed reactor, was successfully established. X-ray diffraction, temperature-programmed reduction, and X-ray photoelectron spectroscopy were used to characterize the catalyst. Introduction of Cr to Cu30/γ-Al2O3 was found to substantially enhance the dispersion of Cu0 particles, which are believed to be the active sites for the reductive N-alkylation. The reaction conditions were optimized and a series of alcohols and nitrobenzenes were converted into N-alkylated anilines in more than 90 % yield by use of this catalyst.