Electron Mediated Conversion of Silylones to Six-membered Cyclic Silylenes.
Abstract: A silicon atom in the zero oxidation state stabilized by two carbene ligands is known as silylone. There are two pairs of electrons on the silicon atom, which were recently confirmed both by experimental and theoretical charge density investigations. The silylone is stable up to 195 °C in an inert atmosphere. However, a substoichiometric amount (33 mol%) of potassium metal triggers the activation of the unsaturated C:Si:C back-bone leading to a selective reaction with a tertiary C-H bond in an atom economical approach to form an isomer (silylene with three coordinate silicon) of the silylone. Cyclic voltammetry shows that this reaction proceeds via formation of a silylone radical anion intermediate.