The reaction between p-nitrosonitrobenzene and the tetramethylpropylenediamine-copper(i) complex yields a dinuclear complex that is structurally and electronically similar to side-on peroxo species known in Cu/O2 chemistry. The complex reacts with di-tert-butylphenolate via nitrene transfer, as observed through an intermediate and the aminophenol product obtained upon reductive work-up.