Germylene, intramolecular insertion

The authors proposed a mechanism involving an a-Me migration from Ge to Ru, to produce a Ru = Ge species, followed by intramolecular insertion of the germylene into a Ru-GeMe3 bond (see Section III,A,3). 

Quantum-chemical calculations have been used to probe all the characteristic chemical reactions of CAs (at least in the case of silylenes and germylenes). The theoretical studies cover intramolecular rearrangements, insertions into 0-bonds, additions to double and triple bonds and dimerizations. Note that experimental data on the mechanisms of these reactions are still scarce and the results of theoretical studies are needed to understand the main trends in the reactivity of germylenes, stannylenes and plumbylenes. 

Figure 3 Thermal generation of a germylene followed by intramolecular C-H bond insertion...

Whether carbene, germylene, and silylene are justifiable terms for stabilized versions of the reactive species is a very debatable question [28], However, for synthetic chemists, the most important issue is to know whether these stable species feature the reactivity of transient carbenes. Formation of azaphospholidines upon thermolysis (intramolecular carbene insertion into a carbon-hydrogen bond), cyclopropanation reactions, and [l + l]-addition to isocyanides giving keteneimines... 

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