Palladium-catalyzed synthesis of a phosphine oxide with a chiral phosphorus center via C-H phosphination

A new phosphine oxide with a chiral phosphine center was synthesized from a bis(biphenyl)phosphine oxide by dehydrogenative intramolecular cyclization via P-H and C-H bond activation under palladium catalysis. The absolute configuration of one enantiomer of the phosphine oxide was determined by single crystal X-ray structure analysis. By reducing the phosphine oxide, the corresponding phosphine, which also has a chiral center, was produced. The phosphine compounds could be optically resolved by chiral HPLC column chromatography.