Direct Substitution of 2‐Aminotropones with Potassium Allyltrifluoroborates through Transition‐Metal‐Free C–N Bond Cleavage

The poor nucleofugality of the amino group renders the C–N bond functionalization of primary aromatic amines highly challenging. Herein, we report a direct substitution reaction of 2‐aminotropones, bearing a unique non‐benzenoid seven‐membered aromatic ring that exists in some natural products and bioactive molecules, with potassium allyltrifluoroborates through C–N bond cleavage under transition‐metal‐free conditions. The amino group of 2‐aminotropones were directly substituted with potassium allyltrifluoroborates in the presence of sodium bicarbonate, delivering structurally diverse 2‐allyltropones in moderate to good yields. The reaction is free of directing groups, activating groups and transition metals, providing a convenient method to access substituted tropones.