A palladium-catalyzed construction of amino β-lactone derivatives is described herein. This method applies readily available aryl amines and alkenyl carboxylic acids as starting materials, providing the amino β-lactone under mild reaction conditions in one step. The deuterium labeling experiment revealed that the β-H elimination process after aminopalladation was effectively suppressed under the excess amount of I –, thus enabling further oxidation and reductive elimination to afford the target amino β-lactones.