PIDA‐Enabled C3‐Amination of Imidazopyridines with Primary Aromatic Amines Using Rongalite as In Situ C1 Source

Abstract Imidazo[1,2‐a]pyridine represents a significant heterocyclic scaffold, and its C3‐aminated derivatives demonstrate enhanced bioactivity. However, employing primary arylamines directly as aminating agents remains challenging to date. Herein, we report the PIDA‐enabled C3‐amination of imidazopyridines employing primary aromatic amines as the amination reagents, with rongalite as an in situ C1‐building block. This approach addresses the substrate scope limitations in C3‐amination reactions of imidazopyridines using primary aromatic amines. Mechanistic investigations have demonstrated that rongalite serves as a reactive C1 synthon, initially enabling C3‐aminomethylation of imidazopyridines with primary aromatic amines, followed by PIDA‐enabled 1,2‐ ipso ‐migration to achieve C3‐amination. This C3‐amination protocol is highly efficient and practicable, exhibiting remarkable substrate generality.