The aqua-soluble multinuclear copper(II) compounds [Cu-2(mu-H(2)tea)(2){mu(3)-Na-2(H2O)(4)}(mu(6)-pma)](n)center dot 10nH(2)O (1) and [O subset of Cu-4(tea)(4)(BOH)(4)][BF4](2) (2) (H-3 tea = triethanolamine, H(4)pma = pyromellitic acid) have been applied as efficient catalysts for the mild, selective and clean oxidation of benzyl alcohols to benzaldehydes, which proceeds in sole water as solvent at 50 degrees C, under atmospheric pressure of air(or O-2) as oxidant, and is mediated by TEMPO radical. Molar yields of benzaldehydes (based on alcohol) up to 99% have been achieved (with a high selectivity). Attractive features of these catalytic systems include the use of organic-solvent-free reaction medium, air or dioxygen as oxidant, and aqua-soluble copper catalysts that are readily available by self-assembly. (C) 2009 Elsevier B.V. All rights reserved.