A Stable N‐Heterocyclic Silylene with a 1,1′‐Ferrocenediyl Backbone

The N‐heterocyclic silylene [{Fe(η(5)‐C(5)H(4)‐NDipp)(2)}Si] (1DippSi, Dipp=2,6‐diisopropylphenyl) shows an excellent combination of pronounced thermal stability and high reactivity towards small molecules. It reacts readily with CO(2) and N(2)O, respectively affording (1DippSiO(2))(2)C and (1DippSiO)(2) as follow‐up products of the silanone 1DippSiO. Its reactions with H(2)O, NH(3), and FcPH(2) (Fc=ferrocenyl) furnish the respective oxidative addition products 1DippSi(H)X (X=OH, NH(2), PHFc). Its reaction with H(3)BNH(3) unexpectedly results in B−H, instead of N−H, bond activation, affording 1DippSi(H)(BH(2)NH(3)). DFT results suggest that dramatically different mechanisms are operative for these H−X insertions.