Expedient Synthesis of <i>N</i>‐Methyl‐ and <i>N</i>‐Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles

Abstract

Abstract N ‐Methyl‐ and N ‐alkylamines represent important fine and bulk chemicals that are extensively used in both academic research and industrial production. Notably, these structural motifs are found in a large number of life‐science molecules and play vital roles in regulating their activities. Therefore, the development of convenient and cost‐effective methods for the synthesis and functionalization of amines by using earth‐abundant metal‐based catalysts is of scientific interest. In this regard, herein we report an expedient reductive amination process for the selective synthesis of N ‐methylated and N ‐alkylated amines by using nitrogen‐doped, graphene‐activated nanoscale Co 3 O 4 ‐based catalysts. Starting from inexpensive and easily accessible nitroarenes or amines and aqueous formaldehyde or aldehydes in the presence of formic acid, this cost‐efficient reductive amination protocol allows the synthesis of various N ‐methyl‐ and N ‐alkylamines, amino acid derivatives, and existing drug molecules.