Reactions of 7,8-disilabicyclo[2.2.2]octa-2,5-dienes. Evidence for the transient existence of a disilene

Tetramesityldisilene, a Stable Compound Containing a Silicon-Silicon Double Bond

“…The electronic structure of silicon is analogous to that of carbon, but the diversity of silicon chemistry has been limited by the lack of doubly bonded compounds, despite numerous attempts to synthesize them over the past six decades (1). Even compounds with a Si=C bond are rare, the first isolable one having been reported only this year (2 (3,4). They have also attracted the attention of theoreticians (5).…”

Theoretical Calculations on the Tetramethyldisilene Rearrangement: A New Approach to an Old Mechanistic Problem

“…The most useful piece of quantitative information available for this reaction is the final product ratio of the 1,3‐disilacyclobutanes GS 5 to GS 7 and GS 8 . The ratio of GS 5 to GS 7 and GS 8 varies from 3.0:1 at 500 °C and 0.01 Torr4 to 2:1 at 700 °C and 0.15 Torr,7 although in the second instance the reaction was started from GS 2 . Earlier kinetic data for the reactions in Scheme were obtained from numerical integration procedures by Davidson et al 9.…”

“…The first multiply bonded silicon compounds were reported by Gusel′nikov and Flowers1, 2 in the late 1960s. Although it took more than a decade thereafter3 to synthesize a stable disilene, evidence for its presence as a reactive intermediate was abundant in earlier literature 4–6. The first of such observations was made by Roark and Peddle in 1972 4.…”

“…Although it took more than a decade thereafter3 to synthesize a stable disilene, evidence for its presence as a reactive intermediate was abundant in earlier literature 4–6. The first of such observations was made by Roark and Peddle in 1972 4. The authors wanted to generate a disilene by using a retro‐Diels–Alder reaction of 7,8‐disilabicyclo[2.2.2.…”

Selected descriptive and mechanistic considerations of (p-p) (pi) bonded silicon intermediates

“…Alternatively, the disilene 21^ may react with benzaldehyde to directly form Peddle and co-workers (68,69) have shown that disilene may have a good deal of diradical character, thus direct addition is entirely reasonable. This cyclic system is ideally designed to fragment via a concerted reaction to form stilbene and silanone The stereochemistry which might be imparted to the stilbene in this path is obliterated by the high temperature.…”