Synthesis of benzo[4, 5]imidazo[2,1- a ]isoquinolines via intramolecular C–H bond functionalization

The preparationof benzo[4,5]imidazo[2,1-a] isoquinolineshas been achieved using PdCl2/PPh3 as catalyst.This protocol has such followingadvantages as simple sequential work-up, good selectivity and toleranceuniversality for functional groups. A wide range of (Z)-2-bromovinylamines, andwith-drawing or electron-donating 2-chlorophenylboronic acids were able to undergo sequentialprocess smoothly to generate the corresponding benzo[4,5]imidazo[2,1-a] isoquinolinesproducts with the yield 62~77%.