Synthesis of β‐Aminoketones via Arylboronic Acid Catalyzed Decarboxylative Mannich Reactions of Enamines and β‐Ketoacids

Herein, we report an arylboronic acid‐catalyzed Mannich reaction of β‐ketoacids and enamines. In this transformation, the enamine served as an imine equivalent to react with the β‐ketoacids with the delivery of CO2 as the sole by‐product. A series of β‐aminoketones were obtained in yields of 48% to 96% under mild reaction conditions with 5 mol% catalyst loading. Additionally, the product was synthesized on a gram scale and further transformations were carried out. A possible catalytic cycle was proposed.