Preparation of 2‑Amino-3-arylindoles via Pd-Catalyzed Coupling between 3‑Diazoindolin-2-imines and Arylboronic Acids as well as Their Extension to 3‑Aryl-3-fluoroindolin-2-imines

2-Amino-3-arylindoles were conveniently prepared from 3-diazoindolin-2-imines and arylboronic acids through palladium carbene intermediates in moderate to excellent yields. The synthesized 2-amino-3-arylindoles could be fluorinated with NFSI to afford 3-aryl-3-fluoroindolin-2-imines.