Synthesis and Reactivity of a Neutral Homocyclic Silylene.

Isolation of the neutral homocyclic silylene 2 is possible via amine ligand abstraction with potassium graphite (KC8) and subsequent reaction with SiMe3Cl from a bicyclic silicon(I) amide J. This reaction proceeds via an anionic homoaromatic silicon ring compound 1 as an intermediate. The twofold-coordinated silicon atom in the homocyclic silylene 2 is stabilized by an allyl-type π-electron delocalization. 2 reacts in an oxidative addition with 2 equivalents of MeOH and in cycloadditions with ethene, phenylacetylene, diphenylacetylene and with 2,3-dimethyl-1,3-butadiene to afford novel functionalized ring compounds.