Small Molecule Activation on a Base-stabilized Phosphinidene

Reduction of (NP)PCl₂ (NP=phosphinoamidinate [PhC(NAr)(=NPPrⁱ ₂ )]^- ) with KC₈ affords the phosphinoamidinato-supported phosphinidene (NP)P (9). Reaction of 9 with a N-heterocyclic carbene (MeC(NMe))₂ C: results in the NHC-adduct NHC→P-P(Prⁱ ₂ )=NC(Ph)=NAr featuring an iminophosphinyl group. Reactions of 9 with HBpin and H₃ SiPh led to the metathesis products (NP)Bpin and (NP)SiH₂ Ph, respectively, whereas with HPPh₂ a base-stabilized phosphido-phosphinidene, the product of N-P and H-P bond metathesis, was obtained. Reaction of 9 with tetrachlorobenzaquinone results in oxidation of P(I) to P(III), accompanied by oxidation of the amidophosphine ligand into P(V). Addition of benzaldehyde to 9 results in a phospha-Wittig reaction affording a product of P=P and C=O bond metathesis. Related reaction with phenylisocyanate results in a product of N-P(=O)Prⁱ ₂ addition to the C=N bond of an intermediate iminophosphaalkene to produce a phosphinidene intramolecularly stabilized by a diaminocarbene.