 on the basis of mechanism - driven 
 reaction design , a pd - catalyzed 
 nucleophilic fluorination of aryl bromides and iodides has been developed . 
 
 the method exhibits a broad substrate scope , especially with respect 
 to nitrogen - containing heteroaryl bromides , and proceeds with minimal 
 formation of the corresponding reduction products . 
 a facilitated ligand 
 modification process was shown to be critical to the success of the 
 reaction . 
Supplementary Material