text: The parent compound of the phosphines is PH, called phosphine in the US and British Commonwealth, but phosphane elsewhere. Replacement of one or more hydrogen centers by an organic substituents (alkyl, aryl), gives PHR, an organophosphine, generally referred to as phosphines.
  From the commercial perspective, the most important phosphine is triphenylphosphine, several million kilograms being produced annually. It is prepared from the reaction of chlorobenzene, PCl, and sodium.  Phosphines of a more specialized nature are usually prepared by other routes.  Phosphorus halides undergo nucleophilic displacement by organometallic reagents such as Grignard reagents.  Organophosphines are nucleophiles and ligands.  Two major applications are as reagents in the Wittig reaction and as supporting phosphine ligands in homogeneous catalysis.
  Their nucleophilicity is evidenced by their reactions with alkyl halides to give phosphonium salts. Phosphines are nucleophilic catalysts in organic synthesis, e.g. the Rauhut–Currier reaction and Baylis-Hillman reaction. Phosphines are reducing agents, as illustrated in the Staudinger reduction for the conversion of organic azides to amines and in the Mitsunobu reaction for converting alcohols into esters. In these processes, the phosphine is oxidized to phosphorus(V). Phosphines have also been found to reduce activated carbonyl groups, for instance the reduction of an α-keto ester to an α-hydroxy ester.