Azidocarbonyl-substituted cubanoureas

Despite the angular strain associated with the assembly of small rings, 1,2-diisocyanatocubane reacts with trimethylsilyl azide under mild conditions to form a hexacyclic ring assembly that contains an imidazolidone ring fused to one edge of cubane. This compound was identified as an azidocarbonyl-substituted cubanourea by means of X-ray crystal structure analysis of the nitro-derivative, the energetic compound N-azidocarbonyl-N¹-nitrocubanourea.