Transamidation of amides with amines under solvent-free conditions using a CeO₂ catalyst

Among various metal oxides, cerium oxide (CeO₂) shows the highest catalytic activity for transamidation of picolinamide with n-octylamine. CeO₂ acts as a reusable and effective heterogeneous catalyst for transamidation under solvent-free conditions. Transamidation of a variety of amides and amines produced the corresponding N-alkyl amides in high yields. This method provides the first example of a heterogeneous catalyst for transamidation using aliphatic amines as substrates. Characterization of acid–base properties and kinetic studies suggest that the cooperation of the weak Lewis acid sites and adjacent strong base sites play important roles in the transamidation reaction.