(Chloromethylene)triphenylphosphorane is the organophosphorus compound with the formula Ph3P=CHCl (Ph = phenyl).

It is a white solid but is usually generated and used in situ as a reagent in organic synthesis.

The reagent is prepared from the chloromethylphosphonium salt [Ph3PCH2Cl]Cl by treatment with strong base.

The phosphonium compound is generated by treatment of triphenylphosphine with chloroiodomethane.

[1] (Chloromethylene)triphenylphosphorane converts aldehydes to vinyl chlorides: These vinyl chlorides undergo dehydrochlorination to give alkynes:[2]