New Way to Methylene‐2 H ‐azirines and Their Use as Powerful Intermediates for the Stereo‐ and Regioselective Synthesis of Compounds with Vinylamine Substructure

New and relatively stable methylene‐2 H ‐azirines 1 have been prepared by photolysis of allenyl azides or from 2‐halo‐2 H ‐azirines by elimination of HX (X = halogen). The reaction of these methylene‐2 H ‐azirines with nucleophiles led to the highly stereo‐ and regio‐selective formation of novel 1‐aminovinyl derivatives with good to excellent yields. The trapping reactions of the less stable methylene‐2 H ‐azirines gave rise to similar results. Moreover, we were able to prove that the previous report on 2‐(phenylsulfonyl)acrylonitrile ( 9 ) was based on incorrect data. For this reason, the latter compound can be supposed to be firstly described in this paper. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)