Regioselective Synthesis of Dimethylamino‐ or Arylalkylamino‐‘‘Crowned” Tröger's Base Analogues Under Vilsmeier–Haack Conditions
Under typical Vilsmeier–Haack conditions, Troger's base undergoes regioselective dimethylamino or arylalkylamino substitution on the methano bridge of the dibenzo[b,f][1,5]diazocine system, revealing a hitherto unknown reactivity pattern. The regioselectivity of the reaction was established by NMR spectroscopy and X-ray crystallography. The key feature of this reaction is its generality; it is compatible with different substitution patterns on the Troger's base and can be performed with DMF as well as with other formamides. The wide scope of the reaction has been applied in the synthesis of several uncommon Troger's base analogues.