Enantioselective Halocyclization Using Reagents Tailored for Chiral Anion Phase-Transfer Catalysis

A chiral anion phase-transfer system for enantioselective halogenation is described. Highly insoluble, ionic reagents were developed as electrophilic bromine and iodine sources, and application of this system to <i>o</i>-anilidostyrenes afforded halogenated 4<i>H</i>-3,1-benzoxazines with excellent yield and enantioselectivity.