The Versatile Chemistry of Disilenides: Disila Analogues of Vinyl Anions as Synthons in Low-valent Silicon Chemistry

Since the first isolation of a disila analog to vinyl anion synthons, namely lithium disilenide Tip(2)Si=Si(Tip)Li (Tip: 2,4,6-triisopropylphenyl), the number of available disilenides and their synthetic applications have rapidly expanded. Derivatives with aryl, silyl, alkyl, and hydrogen substituents have been reported and even one cyclic derivative is available. Disilenides can be used to introduce the Si=Si unit to a variety of organic and inorganic substrates. Depending on whether products feature sufficiently reactive residual functionality, the Si=Si bond is either retained or undergoes further (so far intramolecular) transformations. Heteroatom-substituted disilenes are easily accessible via disilenides. Using Tip(2)Si=Si(Tip)Li as a starting material, for instance, a variety of otherwise inaccessible compounds can be prepared: conjugated systems with more than one Si=Si unit, eta(1)-transition-metal complexes, functional homo- and heteronuclear silacycles, and molecular silicon clusters with substituent-free vertices. In this review article, an account on the chemistry of disilenides is given.