beta-Spironaphthoxazines 1 undergo oxidative addition of the C-N bond of the indoline moiety at ambient temperature upon treatment with the labile Ru(0) precursor, Ru(eta(4)-cycloocta-1,5-diene)(eta(6)-naphthalene) (2), to give the Ru(II) complex with the naphtholato-tethered 1,4-diazabuta-1,3-diene ligand 3. The reaction should be triggered by chelation of the isomeric azanaphthoquinone structure, which should bring the C-N bond to the position suitable for the oxidative addition.