A novel route to the trisilacyclobutane moiety. A possible silene-disilene reaction

Silenes: Connectors between classical alkenes and nonclassical heavy alkenes

“…In the thermolytic formation of the transient 2-amino-2-siloxysilenes (75a-75c, Scheme 22) very little dimer formation was observed [8], and potassium silenolates revealed no tendency for dimerization [73]. Formation of dimers from lithium silenolates was suggested but not proven [72,121].…”

The First Isolable 2‐Silenolate

“…So far 1‐silenolates have not been made, and even computational studies of these species are absent. With regard to 2‐silenolates, there are only a handful of reports from the groups of Bravo‐Zhivotovskii and Apeloig2, 3 and Ishikawa and Ohshita 4. It was found that 2‐silenolates with bulky alkyl or aryl substituents on the carbonyl carbon atom are moderately stable at low temperatures, thus allowing their characterization by NMR spectroscopy.…”

Silylenes, Silenes, and Disilenes: Novel Silicon‐Based Reagents for Organic Synthesis?

“…[22] Increased stability is also realised with silenes influenced by reversed Si=C bond polarisation, that is, an Si dÀ =C d + instead of Si d + =C dÀ polarisation, effected by p-donor substituents on the carbon atom. [28,29] In particular, Ottosson has exemplified this concept in a recent report describing an isolable silenolate 10 a although, having a very long Si À C bond (1.926 ), this is probably better described by the alternative resonance structure 10 b. [25,26] Whilst the 2-siloxysilenes of Brook show this reversed Si=C bond polarisation effect, other examples are seen with the silatriafulvene 9 [27] and silenolates.…”

“…This leads to a lower release in energy upon dimerisation,24 and slower reaction rates for addition of water and alcohols to the silenes 25. 26 Whilst the 2‐siloxysilenes of Brook show this reversed SiC bond polarisation effect, other examples are seen with the silatriafulvene 9 27 and silenolates 28. 29 In particular, Ottosson has exemplified this concept in a recent report describing an isolable silenolate 10 a although, having a very long SiC bond (1.926 Å), this is probably better described by the alternative resonance structure 10 b 30…”