Khan and co-workers recently developed chemoselective bromination of active methylene compounds by employing the vanadium pentoxide catalyzed (V 2 O 5 ) oxidation of ammonium bromide (NH 4 Br) by hydrogen peroxide (H 2 O 2 ). [5] The reaction conditions of this method are very mild, and the reaction affords a product in high yield with high chemoselectivity. However, there are still some problems such as the use of a toxic vanadium compound as the catalyst ...
