Phenol ring nitration induced by the unprecedented reduction of the Cu(II) centre by nitrogen dioxide

Nitrogen dioxide ((NO2)-N-center dot) induces tyrosine nitration through a radical mechanism in biological systems. Two copper(II) complexes, 1 and 2, with ligands L-1 and L-2 [L-1 = 2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)(isopropyl)amino)methyl)phenol; L-2 = 6,6'-(((2-(dimethylamino)ethyl)azanediyl)bis(methylene))bis(2,4-di-tert-butylphenol)], respectively, have been made to react with (NO2)-N-center dot. In both cases, the reduction of the copper(II) center was observed in the presence of (NO2)-N-center dot which induces phenol ring nitration through nitronium ion (NO2+) formation.