Chlorodiphenylphosphine is used to introduce the diphenylphosphinyl moiety by aryl ortho-lithiation. It is also used as an intermediate to make antioxidants, flame retardants, stabilizers, catalysts, photoinitiators, and optical brighteners. Used as a halogenation reagent for the conversion of alcohols into halides, in the preparation of solid-phase reagent for the conversion of alcohols to alkyl halides.