(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. It is structurally and chemically related to methylenetriphenylphosphorane.
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.
(Chloromethylene)triphenylphosphorane converts aldehydes to vinyl chlorides: RCHO + Ph3P=CHCl → RCH=CHCl + Ph3PO These vinyl chlorides undergo dehydrochlorination to give alkynes: RCH=CHCl + NaN(SiMe3)2 → RC≡CH + NaCl + HN(SiMe3)2
Related compounds (Iodomethylene)triphenylphosphorane (Dichloromethylene)triphenylphosphorane
References