Efficient One-Pot Synthesis of Mono- and Bis[di(2-pyridyl)phosphine Oxides] from Tris(2-pyridyl)phosphine

An efficient one-pot access to di(2-pyridyl)phosphine oxides Py 2 P(R)=O and bis[di(2-pyridyl)phosphine oxides] Py 2 P(O)–Z–P(O)Py 2 has been developed based on the reaction of available tris(2-pyridyl)phosphine with various organic halides, followed by treatment of the resulting phosphonium salts with alkali in situ . The isolated yields of the phosphine oxides were in the range 40–96%.