The reaction of [PdCl2(PCy2H)2] (1) with sodium phenoxide gives, depending on the stoichiometries, the dimers [Pd(mu-PCy2)Cl(PCy2H)]2 (2) or [Pd(mu-PCy2)(PCyOPh)]2 (3). Complex 2 was shown to be an intermediate in the conversion of 1 to 3, which probably occurs with the transfer of a proton from the secondary phosphine to the palladium center, assisted by the phenoxide ion. Elimination of molecular hydrogen and formation of the P-O bonds gives then complex 3.