Nucleophilic addition of CH, NH, and OH bonds to the phosphadiazonium cation and interpretation of 31P chemical shifts at dicoordinate phosphorus centers

The phosphadiazonium cation (Mes*NP)+ undergoes nucleophilic additions with fluorenylidine anion Mes*NH2 and Mes*OH, where Mes* = 2,4,6-tri-tert-butylphenyl, to yield phosphaalkenes and phosphenium cations which show the insertion of the N-P moiety into the H-Y, where Y = C, N, O bonds. A general reaction mechanism is experimentally supported by the separation and characterization of a sigma-complex model of the trapped intermediate, (Mes*NP-PPh3)(SO3CF3), for the insertion mechanism.