Synthesis, and Characterization of an Unsymmetrical 1, 2-Diphosphinoethanide Complex

A palladium 1,2-ethylene-bisphosphine complex prepared by diphosphination of acrylonitrile and subsequent complexation undergoes facile and reversible C deprotonation at a backbone carbon atom. The 1,2-diphosphinoethanide complex that formed was characterized by spectroscopic data and a single-crystal X-ray diffraction study. The reaction may explain the previously observed configurational lability of coordinated 1, 2-bisphosphine ligands with electron-withdrawing substituents.