A niobaziridine hydride system for white phosphorus or dinitrogen activation and N- or P-atom transfer

This short review describes a breakthrough embodied by the synthesis of a niobaziridine hydride complex. This reactive entity reacts directly with white phosphorus to provide a bridging diphosphorus diniobium complex that upon reduction splits to afford a terminal niobium phosphide anion, isolated as its sodium salt. Reactions of the latter with acid chlorides constitute a new synthesis of phosphaalkynes, while treatment with chlorodiorganophosphanes leads to complexed 1,1-diorganophosphanylphosphinidene systems. Additionally, reactions of the sodium salt of the niobium phosphide anion with divalent main group element salts (E = Ge, Sn, or Pb) provide complexed triatomic EP2 triangles. Dinitrogen cleavage was realized via reduction of a heterodinuclear niobium/molybdenum dinitrogen complex, and this provided an entry to a nitrogen-15 labeled terminal nitride anion of niobium as its sodium salt. In a fashion analogous to the aforementioned phosphaalkyne synthesis, acid chlorides are transformed upon reaction with the niobium nitride anion into corresponding nitrogen-15 labeled organic nitriles. Complete synthetic cycles are achieved in both the phosphaalkyne and the organic nitrile syntheses, as the oxoniobium(v) byproduct can be recycled in high yield to the title niobaziridine hydride complex.