Fig. 5: The proposed mechanism of the formation of amides by the reaction of esters with NaAB (a) and with amines (b).

The both reaction including the nucleophilic addition, proton transfer, and elimination in which the molar ratio of NaAB or amine to ester (R’, R” =alkyl, aryl) is 2:1, however, the reaction with NaAB is fast while the reaction with amine is sluggish.