Bis(imino)phosphanes: Synthesis and Coordination Chemistry

Bis(imino)phosphanes can be synthesized efficiently from iminophosphanes and nitrilium triflates, allowing for nonsymmetric substitution at the imine groups. Symmetrically substituted derivatives can even be obtained in a one-pot procedure from primary phosphanes. These potential N,N-bidentate ligands are sensitive toward Cu(II), Zn(II), and rhodium(I) sources, resulting in loss of an imine group. For [RhCl(COD)]₂ this led to an N,P- and P-chelating bimetallic complex. Bis(imino)phosphanes with C-Me substituents rearrange in situ to unique 1,3,5-phosphadiazapentadienes for which a P-coordinated gold(I) complex is reported. The bis(imino)phosphanes are readily oxidized to stable bis(imino)phosphane oxides with aqueous H₂O₂.