Additive‐Free Pd/In2O3‐Catalyzed N‐methylation of Primary Amides by Using Formic Acid

Here we report on the use of formic acid as a green and safe reagent for the N‐methylation of primary amides in the presence of a Pd/In2O3 solid catalyst. No additive is needed and primary amides are selectively N‐methylated in good to excellent yields. The reaction operates through a formylation/reduction pathway, leaving the amide carbonyl untouched. Selective N‐methylation of primary amides is achieved using formic acid as a safe and sustainable methylation agent, over a Pd/In2O3 catalyst. No additive is required. Aromatic primary amides are methylated in good to excellent yields. Formic acid proves its usefulness in allowing fruitful reaction with less reactive substrates and expanding the narrow scope of molecules capable of methylating amides.