We describe here the coupling to transform aryl phosphine derivatives by the cleavage of unactivated C(aryl)–P bonds with chromium catalysis, allowing us to achieve the reaction with alkyl bromides and arylmagnesium reagentsundermildconditions. Mechanistic studies indicate that catalytic cleavage of unactivated C(aryl)–P bonds is due to the in situ formed reactive Cr, followed by transmetalation