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 ( 1DippSi O 2 ) 2 C and ( 1DippSi O) 2 as follow‐up products of the silanone 1DippSi O. 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.