The addition of phenyl lithium (PhLi) to an aromatic 1,3,2,5-diazadiborinine (1) afforded isolable ionic species 2, which can be deemed as an inorganic analogue of a Janovsky complex. X-ray diffraction analysis and DFT studies of 2 indicate the delocalization of π-type electrons mainly over the C-B-C unit in the central B2C2N2 six-membered ring. The reactions of 2 with methyl iodide (MeI) and chloro(tricyclohexylphosphine)gold(i) (Cy3PAuCl) gave 3 bearing a B-Me bond and 4 featuring a B-Au bond, respectively, demonstrating the nucleophilic properties of the tricoordinate boron center in 2. © The Royal Society of Chemistry 2017.