Efficient copper(I)-catalyzed coupling of secondary phosphine oxides with aryl halides

A catalytic system has been developed for the efficient synthesis of tertiary arylphosphine oxides by coupling of readily available secondary phosphine oxides with aryl bromides or iodides in the presence of copper(I) iodide as a catalyst and (S)-α-phenylethylamine as a ligand. The system exhibits high activity in the coupling of secondary diaryl-, alkylaryl- and dialkylphosphine oxides.