Insertion of a Nontrigonal Phosphorus Ligand into a Transition Metal-Hydride: Direct Access to a Metallohydrophosphorane.

The synthesis and reactivity of an NPN-chelating ligand containing a nontrigonal phosphorous triamide center (L1 = P(N( o-N(2-pyridyl)C6H4)2) is reported. Metalation of L1 with RuCl2(PPh3)3 gives RuCl2(PPh3)(L1) (2). By contrast, metalation of L1 with RuHCl(CO)(PPh3)3 yields RuCl(CO)(PPh3)(L1H) (3), a chelated 10-P-5 ruthenahydridophosphorane, via net insertion into the Ru-H bond. Hydride abstraction from 3 with Ph3CPF6 gives [RuCl(CO)(PPh3)(L1)]PF6 (4); reaction of 4 with NaBH4 returns 3.