Trivalent phosphorus is easily oxid

Trivalent phosphorus is easily oxidized. In contrast with ammonia and amines, phosphine and its mono and dialkyl derivatives are pyrophoric, bursting into flame on contact with the oxygen in air. The affinity of trivalent phosphorus for oxygen (and sulfur) has been put to use in many reaction systems, three of which are shown here. The triphenylphosphine oxide produced in reactions 1 & 3 is a very stable polar compound, and in most cases it is easily removed from the other products. Reaction 2 is a general formulation of the useful Corey-Winter procedure for converting vicinal glycols to alkenes.