First Direct Evidence for Nitrile Imine‐Diazo Isomerization. Synthesis of Relatively Stable N‐Silylated Nitrile Imines

The title reaction 1a → 1b takes place between −78 and +55 °C, the rearrangement temperature depending on the substituents. The nitrile imines 1a can be characterized in solution by NMR and IR spectroscopy. Compounds 1a, E = SiMe3 and SiPh3, have also been trapped with methanol and with methyl acrylate (cycloaddition).