Redirecting C‐H Activation Capacity From <scp> N ¹ </scp> to <scp> N ³ </scp> Atom: Palladium‐Catalyzed Late‐Stage Acetoxylation of <scp> N ⁹ </scp> ‐Aryl/Benzylpurines

ABSTRACT Herein, we report a palladium‐catalyzed C‐H acetoxylation of N 9 ‐aryl/benzylpurines by using PhI(OAc) 2 as the stoichiometric oxidant. Despite four interferential nitrogen atoms in the purine skeleton, which all have the ability to participate in metal coordination, we also redirect the C‐H activation capacity from the N 1 to the N 3 atom using appropriate steric shielding with C 6 ‐dialkylamino groups. The reaction is scalable to the gram level, demonstrating its effectiveness in late‐stage construction of N 9 ‐substituted purines in pharmaceutical chemistry and synthetic methodology. Meanwhile, the acetoxyl group is a removable group, which can be easily converted to other various valuable groups.