text: Pd(PPh) is widely used as a catalyst for palladium-catalyzed coupling reactions. Prominent applications include the Heck reaction, Suzuki coupling, Stille coupling, Sonogashira coupling, and Negishi coupling. These processes begin with two successive ligand dissociations followed by the oxidative addition of an aryl halide to the Pd(0) center:
  :Pd(PPh) + ArBr → PdBr(Ar)(PPh) + 2 PPh