An intermolecular FLP System derived from an NHC-coordinated trisilacyclopropylidene

Abstract

The NHC-coordinated trisilacyclopropylidene (A) is shown to behave as the basic component of an FLP used in combination with the Lewis acid B(C₆F₄H)₃ (i.e. B(2,3,5,6-C₆F₄H)₃). This FLP cleaves dihydrogen highly selectively at room temperature giving rise to the ionic compound [(NHC)SiH(Mes₂SiSiMes₂)][HB(C₆F₄H)₃] 1 in 90% isolated yield. Further reaction of the FLP with Ph₂NH and acetone yielded compounds [(NHC)SiH(Mes₂SiSiMes₂)][Ph₂NB(C₆F₄H)₃] 2 and [(NHC)SiH(Mes₂SiSiMes₂)][MeC(CH₂)OB(C₆F₄H)₃] 3 in 75% and 80% yield, respectively. Reaction of the FLP with N₂O results in the oxidation of the silylene center affording [((NHC)SiOB(C₆F₄H)₃)(Mes₂SiSiMes₂)] 4 in 53% yield. These products are spectroscopically characterized and an X-ray structure of 4 is reported.