Alexander J. Blake, Bernard A. J. Clark, Hamish McNab and Craig C. Sommerville
Flash vacuum pyrolysis (FVP) of the azide 4 leads to imidazo[1,2-a]benzimidazole 8 exclusively, via highly regioselective insertion of the triplet nitrene intermediate 5 into the 2-CH bond of the imidazole ring. The X-ray crystal structure and NMR spectroscopic properties of 8 are discussed in detail.