Selective N‐Monomethylation of Amines and Nitroarenes using Methanol over an Encapsulated Iridium Nanocatalyst

Abstract A highly selective N‐monomethylation of aniline and nitrobenzene using methanol as methylating reagent was achieved with high efficiency when using an encapsulated iridium nanocatalyst. A wide range of amines and nitro compounds reacted well in the established catalytic system with moderate to excellent product yields and good functional group tolerance. The transfer hydrogenation and successive cyclization coupling reaction of ortho ‐phenylenediamine with methanol to afford benzimidazole and N ‐methylbenzimidazole was also efficiently realized under moderate reaction conditions. Recycling experiments showed that the iridium nanocatalyst had a good stability without obvious activity loss.