Evidence for phthalimidonitrene as a common intermediate in several extrusion reactions

A common intermediate, presumably phthalimidonitrene 1, is generated in the thermolysis of the aziridinobenzofurans 3(R = Ac, CO2Me, Bz, COBut and CN) as well as the sulphimide 4, and the azabenzonorbornadiene 5. The transfer of 1 shown in Scheme 1 is zero order in 2-acetylbenzofuran providing further evidence against a concerted bimolecular mechanism 10 for ‘nitrene’ transfer.