Details

Autor(en) / Beteiligte

• Georg, Isabelle
• Bursch, Markus
• Stückrath, Julius B.
• Alig, Edith
• Bolte, Michael
• Lerner, Hans‐Wolfram
• Grimme, Stefan
• Wagner, Matthias

Titel

Building up Strain in One Step: Synthesis of an Edge‐Fused Double Silacyclobutene from an Extensively Trichlorosilylated Butadiene Dianion

Ist Teil von

• Angewandte Chemie (International ed.), 2020-09, Vol.59 (37), p.16181-16187

Auflage

International ed. in English

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The exhaustive trichlorosilylation of hexachloro‐1,3‐butadiene was achieved in one step by using a mixture of Si2Cl6 and [nBu4N]Cl (7:2 equiv) as the silylation reagent. The corresponding butadiene dianion salt [nBu4N]2[1] was isolated in 36 % yield after recrystallization. The negative charges of [1]2− are mainly delocalized across its two carbanionic (Cl3Si)2C termini (α‐effect of silicon) such that the central bond possesses largely C=C double‐bond character. Upon treatment with 4 equiv of HCl, [1]2− is converted into neutral 1,2,3,4‐tetrakis(trichlorosilyl)but‐2‐ene, 3. The Cl− acceptor AlCl3, induces a twofold ring‐closure reaction of [1]2− to form a six‐membered bicycle 4 in which two silacyclobutene rings are fused along a shared C=C double bond (84 %). Compound 4, which was structurally characterized by X‐ray crystallography, undergoes partial ring opening to a monocyclic silacyclobutene 2 in the presence of HCl, but is thermally stable up to at least 180 °C. Upcycling: A sixfold trichlorosilylated butadiene dianion is accessible in one step from hexachlorobutadiene and the Si2Cl6/Cl− system. Cl− ion with AlCl3 causes a double cyclization reaction and quantitatively forms a six‐membered double silacyclobutene.