First Insertions of Carbene Ligands into Ge−N and Si−N Bonds

The insertion of carbene ligands into Ge−N (three examples) and Si−N (one example) bonds has been achieved for the first time by treating Fischer carbene complexes (M=W, Cr) with bulky amidinatotetrylenes (E=Ge, Si). These reactions, which start with a nucleophilic attack of the amidinatotetrylene heavier group 14 atom to the carbene C atom, proceed through a stereoselective insertion of the carbene fragment into an E−N bond of the amidinatotetrylene ENCN four‐membered ring, leading to [M(CO) 5 L] derivatives in which L belongs to a novel family of tetrylene ligands comprising an ECNCN five‐membered ring.