Palladium catalyzed-dehalogenation of aryl chlorides and bromides using phosphite ligands

The catalytic system based on Pd-phosphite for the dehalogenation reactions of aryl chlorides and bromides is described. The Pd-phosphite catalyst effectively promoted the dehalogenation of aryl halides to give dehalogenated products in moderate to excellent yields. The aryl chlorides required strong bases such as NaO^tBu for this transformation, whereas the aryl bromides were dehalogenated in the presence of weak bases such as Cs₂CO₃. This catalytic system exhibited tolerance to functional groups such as methoxy, amine, hydroxyl, ether, amide, benzyl and ketone groups. It also demonstrated chemoselectivity in that bromochlorobenzene was converted only to chlorobenzene.