Stereoselective polycyclisations of allyl and enyne silanes: evidence for a bicyclo[3.2.0]hept-1(7)ene structure

• Published in: Journal of organometallic chemistry Vol. 643; pp. 324 - 330
• Main Authors: Oba, Gabriel, Moreira, Georges, Manuel, Georges, Koenig, Max
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier B.V 01.02.2002; Elsevier
• Subjects: Allyl silanes; Bicyclo[3.2.0]hept-1 ene; Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Cyclo and spirozirconation; Enyne silanes; Metathesis reactions; Photocycloaddition; Physical Sciences; Science & Technology; Sila-3-bicyclo[3.2.0]heptanes; Allyl silanes; Enyne silanes; Photocycloaddition; Cyclo and spirozirconation; Bicyclo[3.2.0]hept-1 ene; Metathesis reactions; Sila-3-bicyclo[3.2.0]heptanes; sila-3-bicyclo[3.2.0]heptanes bicyclo[3.2.0]hept-1 ene; ROUTE; allyl silanes; MECHANISM; COMPLEXES; photocycloaddition; METAL-PROMOTED CYCLIZATION; metathesis reactions; enyne silanes; SPIROZIRCONATION; BICYCLIZATION; cyclo and spirozirconation; DERIVATIVES; METATHESIS
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/S0022-328X(01)01393-6

The intramolecular copper(I)-catalyzed [2+2]-photocycloaddition of diphenyldiallylsilane ( 1) (or tetraallylsilane ( 4)) led to sila-3-bicyclo[3.2.0]heptane ( 3) (or to spiro analogous 6) in the cis (or cis– cis) configuration whereas the α,ω-diiodide ( 2) obtained by cyclozirconation of 1 (or from the homologous tetraiodide 5) followed by addition of n-BuLi, produced the sila-3-bicyclo[3.2.0]heptane ( 3) (or to the spiro analogous 6) in the trans (or trans– trans configuration). The same cyclozirconation reaction, starting from the hetero enyne 7, selectively led to the highly strained silacyclobutene moiety 15 which represents the first stable hetero bicyclo[3.2.0]hept-1(7)ene skeleton, hypothetical intermediate in metathesis reactions. The spirosilanes in cis– cis or trans– trans configuration are obtained by two appropriate methods. The cyclozirconation of enyne silane, led to silacyclobutene which represents the first stable hetero bicyclo[3.2.0]hept-1(7)ene skeleton, hypothetical intermediate in metathesis reaction.