N[double bond, length as m-dash]N bond cleavage in diazirines by a cyclic diborane(4) compound.

Reactions of -carborane-fused diborane(4) with 3-diazirines led to the complete cleavage of the N[double bond, length as m-dash]N bond, with one nitrogen atom being incorporated into the B-B bond. The molecular and electronic structures of the resultant borylnitrogen compounds were confirmed through single-crystal X-ray analyses and computational studies. The related reaction mechanism was investigated using DFT calculations.