Alkylation of [(Diphenylphosphinoyl)cyano] methylenetriphenylphosphorane

Alkylation of [(diphenylphosphinoyl)cyano]methylenetriphenylphosphorane 6 by 1 mol of triethyloxonium tetrafluoroborate yields {[diphenyl(ethoxy)phosphoranylidene]cyano}methyltriphenylphosphonium tetrafluoroborate 7 and N-ethyl[(diphenylphosphinoyl)(triphenylphosphoranylidene)]acetonitrilium tetrafluoroborate 8, the first example of an organophosphorus compound possessing a nitrilium group