Fluorine and Trifluoromethyl Substituted Anilines: Site Selective Metalation and Electrophilic Substitution

All articles of this category When treated with tert -butyllithium in tetrahydrofuran at -50 °C, N -BOC ( tert -butoxycarbonyt) protected fluoroanilines and trifluoromethylanilines undergo metalation at the nitrogenadjacent position. If, however, the nitrogen carries two alkyl or trimethylsilyl groups as substituents and highly polar metalating reagents such as butyllithium activated by N,N,N′N″,N″ -pentamethyldiethylenetriamine ( PMDTA ) or potassium tert -butoxide are employed, the fluoroaniline derivatives are preferentially deprotonated next to the halogen atom.