Three novel coordination compounds, Cu(ca) 2 (Hbae) 2 ( 1 ), Cu(va) 2 (Hbae) 2 ( 2 ) and Cu 4 (va) 4 (bae) 4 ·H 2 O ( 3 ), have been prepared by self-assembly reactions of copper( ii ) chloride ( 1 and 2 ) or tetrafluoroborate ( 3 ) and CH 3 OH ( 1 and 3 ) or CH 3 CN ( 2 ) solution of 2-benzylaminoethanol (Hbae) and cinnamic (Hca, 1 ) or valeric (Hva, 2 and 3 ) acid. Crystallographic analysis revealed that both 1 and 2 have mononuclear crystal structures, wherein the complex molecules are H-bonded forming extended supramolecular chains. The tetranuclear structure of 3 is based on the {Cu 4 (μ 3 -O) 4 } core, wherein the metal atoms are bound together by μ 3 oxygen bridges from 2-benzylaminoethanol forming an overall cubane-like configuration. The strong hydrogen bonding in 1-3 leads to the joining of the neighbouring molecules into 1D chains. Concentration-dependent ESI-MS studies disclosed the equilibria between di-, tri- and tetranuclear species in solutions of 1-3 . All three compounds act as catalysts for the aerobic oxidation of o -aminophenol to the phenoxazinone chromophore (phenoxazinone synthase-like activity), with the maximum reaction rates of 4.0 × 10 −7 , 2.5 × 10 −7 and 2.1 × 10 −7 M s −1 for 1 , 2 and 3 , respectively, supported by the quantitative yield of the product after 24 h. The dependence of the reaction rates on catalyst concentrations is evidence of reaction orders higher than one relative to the catalyst. Kinetic and ESI-MS data allowed us to assume that the tetranuclear species, originating from 1 , 2 and 3 in solution, possess considerably higher activity than the species of lower nuclearity. Mechanistic and isotopic 18 O-labelling experiments suggested that o -aminophenol coordinates to Cu II species with the formation of reactive intermediates, while the oxygen from 18 O 2 is not incorporated into the phenoxazinone chromophore. Three novel copper coordination compounds bearing aminoalcohol and carboxylate ligands have been synthesized and applied for mild aerobic oxidation of o -aminophenol to the phenoxazinone chromophore.