10.1021/jo991731o.s001
Riccardo Destro
Riccardo
Destro
Vittorio Lucchini
Vittorio
Lucchini
Giorgio Modena
Giorgio
Modena
Lucia Pasquato
Lucia
Pasquato
X-ray Structures and Anionotropic Rearrangements of
Di-<i>tert</i>-butyl-Substituted Thiiranium and Thiirenium Ions. A
Structure−Reactivity Relationship
American Chemical Society
2000
butyl groups
trans tert
thietanium ion
BF
thietium ion
Anionotropic Rearrangements
steric hindrance
8 SbCl 6
Thiirenium Ions
11 SbCl 6
methylthiiranium
rearrangement
intramolecular S N 2 displacements
2000-05-11 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/X-ray_Structures_and_Anionotropic_Rearrangements_of_Di-_i_tert_i_-butyl-Substituted_Thiiranium_and_Thiirenium_Ions_A_Structure_Reactivity_Relationship/3720507
The X-ray structures of <i>c</i>-2,<i>t</i>-3-di-<i>tert</i>-butyl-<i>r</i>-1-methylthiiranium <b>8 </b>BF<sub>4</sub><sup>-</sup>, <i>t</i>-2,<i>t</i>-3-di-<i>tert</i>-butyl-<i>r</i>-1-methylthiiranium ion <b>10 </b>BF<sub>4</sub><sup>-</sup>, and 2,3-di-<i>tert</i>-butyl-1-methylthiirenium <b>11 </b>BF<sub>4</sub><sup>-</sup> have been
determined. The Δ<i>G</i><sup>⧧</sup><sub>298</sub> values for the rearrangements from the cis and the trans <i>tert</i>-butyl groups
of <b>8</b> SbCl<sub>6</sub><sup>-</sup> to thietanium ion (two intramolecular S<sub>N</sub>2 displacements) and for the rearrangement
of <b>11</b> SbCl<sub>6</sub><sup>-</sup> to thietium ion (an intramolecular S<sub>N</sub>2-Vin displacement) are linearly correlated with
the strengths of the C−S breaking bonds, suggesting that the two mechanisms are, in the absence
of steric hindrance, uniquely governed by the nucleofugality of the sulfonium leaving group.