SYNTHESIS AND THERMAL REACTIONS OF 3-TRIMETHYLSILYL-1-PYRAZOLINE

Article abstract of DOI:10.1016/0022-328X(85)80285-0

The compound 3-trimethylsilyl-1-pyrazoline has been synthesized by addition of diazomethane to vinyltrimethylsilane at room temperature.In contrast, addition of trimethylsilyldiazomethane to ethylene at 55 deg C yields 1-trimethylsilyl-2-pyrazoline exclusively.The thermal isomerization of 3-trimethylsilyl-1-pyrazoline to 1-trimethylsilyl2-pyrazoline has been followed kinetically by proton NMR spectroscopy and the reverse reaction has been detected by gas phase pyrolysis.Thermal elimination of nitrogen from either pyrazoline leads to cyclopropyltrimethylsilane, allyltrimethylsilane and E- and Z-1-propenyltrimethylsilane.The relative rates of methylene-H migration to radical centers α and γ to silicon are approximately equal.