Reactions of silyl-substituted Fischer-type carbene complexes with silanes

Silyl-substituted Fischer-type carbene complexes show unique behavior when treated with silanes. In toluene, all three kinds (Cr, Mo, W) of methyldiphenylsilyl-substituted carbene complex react with silanes to give direct insertion products in moderate to high yield. On the other hand, the reactions in THF give different kinds of product depending on the center metal. Thus, in addition to the direct insertion products (Mo), novel reduction-insertion (W) and reduction-carbonyl insertion-silicon migration (Cr) products are obtained in good yields.