Metal-Free N−H Bond Activation by Phospha-Wittig Reagents**

Abstract

N-containing molecules are mostly derived from ammonia (NH3). Ammonia activation has been demonstrated for single transition metal centers as well as for low-valent main group species. Phosphinidenes, mono-valent phosphorus species, can be stabilized by phosphines, giving so-called phosphanylidenephosphoranes of the type RP(PR′3). We demonstrate the facile, metal-free NH3 activation using ArP(PMe3), affording for the first time isolable secondary aminophosphines ArP(H)NH2. DFT studies reveal that two molecules of NH3 act in concert to facilitate an NH3 for PMe3 exchange. Furthermore, H2NR and HNR2 activation is demonstrated.