The molecular dynamics and cycloaddition chemistry of tris(1-indenyl)allylsilane Part 1Generation of the first crystallographically characterized tris(benzonorbornyl)silane

The molecular dynamics and reactivity of tris(inden-1-yl)silane: an NMR spectroscopic and X-ray crystallographic study †

“…The title compound, 9, was readily prepared via quenching of trichlorosilane with an excess of indenyllithium, followed by chromatographic purification on silica. This reaction proved to be much more efficient (64% yield) than the corresponding reactions involving alkyltrichlorosilanes (42% 8 and 13% 16 for 7 and 8, respectively), likely owing to the reduced congestion in 9. As has been observed previously for 7 and 8, compound 9 exists in solution as a statistical (1 : 3 : 3 : 1) mixture of interconverting isomers (Scheme 4).…”

“…15 Moreover, support for the sequential generation of isoindenes in this process was obtained via treatment of 5 with two equivalents In continuation of our studies pertaining to the dynamics of poly(inden-1-yl)silanes, we have reported on the operation of [1,5]-silicon shifts in tris(inden-1-yl)methylsilane, 7, 8 and tris(inden-1-yl)allylsilane, 8. 16 Despite the potential utility of this class of molecules as ligands in the preparation of chiral ansa-metallocene bimetallic precatalysts, to date, 7 and 8 represent the only examples of tris(inden-1-yl)silanes of which we are aware. Moreover, we have demonstrated that these molecules serve as precursors to tris(benzonorbornyl)silanes, a rare class of sterically demanding organosilicon compounds.…”

“…Moreover, we have demonstrated that these molecules serve as precursors to tris(benzonorbornyl)silanes, a rare class of sterically demanding organosilicon compounds. 8, 16 Herein we describe the synthesis, characterisation and molecular dynamics of tris(inden-1-yl)silane, 9, its cycloaddition chemistry, and some preliminary silicon-based reactivity studies involving tris(inden-1-yl)silanes and their corresponding triple Diels-Alder cycloadducts.…”

Diels-Alder Additions as Mechanistic Probes–Interception of Silyl-Isoindenes: Organometallic Derivatives of Polyphenylated Cycloheptatrienes and Related Seven-Membered Rings

“…As depicted in Figure 3 , the exchange pathways between indenyl sites in 3 can be mapped onto a cube (for the eight different indenyl ring environments), and a hypercube (for the exchange of 1 H in sp 2 and sp 3 environments) and again involve successive [1,5]-suprafacial sigmatropic shifts via isoindene intermediates. Gratifyingly, several triple Diels-Alder TCNE adducts, 4 , have been isolated and fully characterized by X-ray crystallography [ 18 , 19 ].…”

Circumambulatory rearrangements of cyclopolyenes containing element-centred migrants

“…17,54 As an example we refer to the major mechanism of the rearrangement of tris(3-indenyl)allylsilane studied by dynamic two-dimensional NMR spectroscopy. 55 The exceptions are the 1,3-shifts of the dipropylboryl group in 9-cyclononatetraenyldipropylborane 56 and compound 11. 50 In the latter case, the rearrangement, which is presumably accompanied by the inversion of configuration of the boron atom, proceeds more slowly than the 1,2-shifts of the dipropylboryl group.…”