Phosphorus Silicon Compounds from the Reduction of MesP(H)SiCl2Ph/Carbene with and without Metal

MesP(H)SiCl2Ph (Mes = 2,4,6-Me3C6H2) (7) with a reactive Si-Cl and P-H bond can easily be reduced by KC(8)or alternatively by a carbene to give remarkable phosphorus silicon compounds.7is readily synthesized from the reaction of MesPH(2)sequentially withnBuLi and PhSiCl(3)in a 1:1:1 ratio. KC(8)reduction of MesP(H)SiCl2Ph (7) in the presence of cyclic alkyl(amino) carbene (cAAC(Me)) gives (MesPH)(3)SiPh (8) and cAAC-stabilized Si2Ph2(9). In addition,9might also be formed by the reduction of PhSiCl(3)using KC(8)in the presence of cAAC(Me). Treatment of MesP(H)SiCl2Ph (7) with IiPr(2)Me(2)(IiPr(2)Me(2)= 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) in a molar ratio of 1:2 results in HCl elimination as IiPr(2)Me(2)center dot HCl. The second equivalent of IiPr(2)Me(2)was used to yield well-defined phosphasilene (10) containing a Ph(Cl)Si=PMes moiety. This unit will gain much application in ligand design because the chlorine atom can readily be replaced by other substituents.