Fine-tuning Substrate--Catalyst Halogen--Halogen Interactions for Boosting Enantioselectivity in Halogen-Bonding Catalysis

Anew approach towards highly enantioselective halogen-bonding  catalysis hasbeen  developed.  In  order  to  circumvent  the intrinsic  issues  of  the  halogen-bond(XB)natureand  consequent unresolved  limitations  in  asymmetric  catalysis,fine-tuned  halogen--halogen   interactions   between   the   substrate   and   XB-donor were designed to pre-organize the  substrate in  the  catalyst’s  cavity and boost enantiocontrol. Remarkable enantioselectivities of up   to   95:5   e.r.   (90% ee)   have   been   achieved   in   a   model dearomatization  reaction  of  halogen-substituted  (iso)quinolines  with tetrakis-iodotriazole multidentate anion-binding catalysts