Room Temperature, Palladium-Mediated P-Arylation of Secondary Phosphine Oxides

We show that a broad range of aryl iodides are efficiently coupled with secondary phosphine oxides using 1 mol % of a catalyst formed in situ from tris(dibenzylideneacetone)dipalladium and Xantphos (1). Scalemic (S)-methylphenylphosphine oxide [(S)-2e] is shown to undergo arylation without detectable stereoerosion. The application of this method to the synthesis of novel P-chiral phosphines and PCP ligands is demonstrated.