Roles of Base in Pd-Catalyzed Chemo- and Regioselective Arylamination/Aryloxygenation of Alleneamide

Allenamines, owing to their unique structural and electronic properties, have attracted considerable attention in organic synthesis, particularly in selective addition reactions at either the proximal or distal double bond. However, achieving high levels of selectivity remains a significant challenge. Herein, we present a detailed computational mechanistic study of the Pd-catalyzed, base-controlled chemo- and regioselective arylamination/aryloxygenation of alleneamides. Our results reveal that the organic base Cy₂NMe primarily acts by deprotonating the nucleophile without directly engaging in the formation of key catalytic intermediates. In contrast, the inorganic base Ag₂CO₃ plays a dual role: (1) releasing CO₂ to generate an oxygen-centered nucleophile and (2) directly coordinating with the Pd catalyst to stabilize essential intermediates. These distinct base behaviors give rise to divergent reaction pathways and selectivity profiles. This work highlights the critical importance of base selection as a powerful strategy for modulating reaction outcomes, providing a rational framework for the future design of highly selective and efficient catalytic processes.