Organometallic compounds, 1,4-addition carbenes from

The reactivity of metal-silylene complexes is more limited than the reactivity of carbene complexes. The cationic base-stabilized ruthenium-silylene complex in Equation 13.37 does not react with olefins or alkynes to undergo [2-1-2] addition reactions. However, a related complex did undergo [2-1-2] addition reactions with isocyanates, as shown in Equation 13.46. Other reactions of silylene complexes are distinct from those of carbene complexes or those of other conventional organometallic compounds. For example, the reaction of the silylene hydride with an acetylene generates a p-silylvinylarene complex... 

The metal carbene moiety is often compatible with a variety of additional functionalization that makes this type of metal carbenes attractive for the synthesis and further elaboration of multifunctional compounds as often encountered in natural products. This trend is also obvious from sugar metal carbenes that upon 0-deprotection can be modified into amphiphilic organometallics revealing a promising supramolecular chemistry. 

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