An Inorganic Huisgen Reaction between a 1,2-Diboraallene and an Azide to Access a Diboratriazole

Regioselective Huisgen cycloaddition reaction between 1,2-diboraallene and azide proceeds under catalyst-free and mild conditions to furnish a diboratriazole (2). X-ray diffraction analysis and computational studies confirmed the delocalization of π electrons over the B₂N₃ five-membered ring of (2), indicating its aromatic features. Molecule (2) spontaneously releases N₂ to form the 2,3-dibora-4-aza-1,3-butenyne derivative (3). The mechanism of a whole reaction profile was extensively investigated by density functional theory (DFT) calculations.