Synthesis and reactivity of the phospha-Grignard reagent Mg(P{SiMe 3}2)Br(thf)

The novel phospha-Grignard reagent Mg(PR2')X(thf) [R' = SiMe3, X = Br (1)/Me (1')] was synthesized and structurally characterized as the phosphide-bridged dimer [1](2). The potential for this compound to behave as a redox-friendly phosphide transfer reagent was probed by its reaction with group 4 metallocene compounds Cp2MCl2 (M = Ti, Zr),resulting in phosphide transfer to zirconium, but reduction of the titanium centre to Ti-III.