Reductive Coupling of P(O)–H Compounds and Aldehydes for the General Synthesis of Phosphines and Phosphine Oxides

A novel strategy for the selective construction of a C(sp3)–P(III) or −P(V) bond from >P(O)–H compounds and aldehydes is disclosed. By using the H3PO3/I2 system, various secondary phosphine oxides could react with both aromatic and aliphatic aldehydes to afford valuable phosphines (isolated as sulfides) and phosphine oxides in good yields. This method features a wide substrate scope and simple reaction conditions and avoids the use of toxic halides and metals.