Pseudo-phosphonium salts

A general synthesis of -(2-oxoalkyl) 0,f7-dialkyl phosphoroselenoates (89) involves the interaction of enol silyl ethers and the pseudo phosphonium salts derived from OTTO-irialkyl phosphoroselenoates and sulphuryl chloride. ... 

The reported 2 e reductive cleavage of phenylsulphonylacetonitrile (PhSO CH CN) and the observation that in protic media the products were PhSO and CH CN, suggested that this reaction could be a useful source of CHjCN. However, careful re-examination showed that in acetonitrile solution the reaction is pseudo one-electron, analogous to the phosphonium and sulphonium salts (Scheme 8), and that phenylsulphonylacetonitrile is sufficiently acidic rapidly to protonate "CHjCN assuming additivity of substituent effects an estimate of pK 14-16 was made for PhSOjCHjCN, cf. pK 31 for CH,CN... 

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