Amide Synthesis from Alcohols and Amines with Ag/Al₂O₃

Significance

Silver clusters immobilized on Al₂O₃ catalyzed the direct amide synthesis from alcohols and amines in the presence of a catalytic amount of Cs₂CO₃. The reaction proceeded with cooperative catalysis of silver cluster, Al₂O₃ and Ce₂CO₃ in refluxing toluene to afford the corresponding amides in 48-93% yield (13 examples). The catalyst was reused without loss of catalytic activity to give 3a (1^st use 91%, 2^nd use 87%, 3^rd use 88%). The authors indicated that this report is the first example of the direct amide synthesis from alcohols and amines promoted by a heterogeneous catalyst.