Some dimeric Cu(II) complexes of 2,2′-dipyridylamine (dipyam), were tested as catalysts for the oxidative coupling of 2,6-dimethylphenol (DMP) to polyphenylene ether (PPE) by dioxygen. The Cu 2dipyam 2(OH) 2I 2 · H 2O complex was able to assist the transformation of DMP in PPE (PPE ≥ 94%) under mild reaction conditions (atmospheric pressure of dioxygen; 298 K; 30 min) at very low concentration ([Cu] = 3.2 × 10 −4; [DMP] [Cu] = 250 ). The diphenoquinone (DPQ), which is the side product of the reaction, could be easily maintained under 4 wt%, with a specificity PPE DPQ ≥ 24 . The polymerization degree of PPE could be tuned ( M ̄ w 45000–196000) by some variables of the catalytic system, as solvent medium, ligand and iodide concentrations, but primarily by using different amounts of OH − anions as co-catalyst. The conditions suitable to obtain a PPE of prefixed characteristics were statistically studied.