Fission of the silicon–phosphorus bond in trimethylsilyldiphenylphosphine has been used to carry out the phosphosilylation of carbon dioxide, carbon disulphide, ethyl and phenyl isothiocyanate, keten, and hexafluoroacetone. In addition, the reactions of the silylphosphine with oxygen, phenyl isocyanate, and sulphur dioxide are described.Structures of the products are suggested based on their infrared and nuclear magnetic resonance spectra.