261353-67-7Relevant academic research and scientific papers
Probing the effect of organic and organometallic functionalization on [1,5]-silicon shifts in indenylsilanes
Stradiotto, Mark,Hazendonk, Paul,Bain, Alex D.,Brook, Michael A.,McGlinchey, Michael J.
, p. 590 - 601 (2000)
Indenylsilanes bearing organic and organometallic substituents have been prepared in order to probe the effect of substitution on the rate of [1,5]-silicon shifts in this class of compounds. In an attempt to prepare 1,1,3-tris(trimethylsilyl)indene (7), the hitherto unknown silicon-functionalized bis(trimethylsilyl)dibenzo[a,d]fulvalene (9) was unexpectedly generated; this species was characterized by use of both NMR spectroscopy and X-ray crystallography and was rationally prepared in 68% yield from 3,3′-bis(1-(trimethylsilyl))-indene (16). The molecular dynamics of 1,3-dimethyl-1-(trimethylsilyl)indene (18) and the crystallographically characterized chromium complex (η61,3-dimethyl-1-exo-(trimethylsilyl)-indene)tricarbonylchromium (22) were examined by use of 1D-selective inversion and 2D-EXSY NMR techniques; surprisingly, the presence of chromium and methyl substituents has a negligible effect on the rate of [1,5]-silicon shifts (ΔG? = 23-24 kcal mol-1) versus the parent compound 1-(trimethylsilyl)indene (3) (ΔG? ≈ 24 kcal mol-1). In the case of 18, the intermediate isoindene 18-iso was intercepted with tetracyanoethylene as the crystallographically characterized [4 + 2] cycloadduct 5,6-benzo-2,2,3,3-tetracyano-1,4-dimethyl-7-(trimethylsilyl)bicyclo(2.2.1)hept- 5-ene (19).
