Secondary alicyclic amines are converted into their corresponding ring-fused imidazoles in a simple procedure consisting of oxidative imine formation followed by a van Leusen reaction. Amines with an existing α-substituent undergo regioselective ring-fusion at the α′-position. This method was utilized in a synthesis of fadrozole.
Key words
C–H bond functionalization - amines - annulation - imidazoles - heterocycles