54828-67-0Relevant academic research and scientific papers
The influence of electronic perturbations on the Sulfur-Fluorine Gauche Effect Dedicated to Prof. Dr. Antonio Togni on the occasion of his 60th birthday.
Thiehoff, Christian,Schifferer, Lukas,Daniliuc, Constantin G.,Santschi, Nico,Gilmour, Ryan
, p. 121 - 126 (2016)
Herein, a solution phase NMR conformer population analysis is employed to probe the effect of remote electronic perturbations on the conformational equilibria of a series of para-substituted β-fluorosulfides (1), sulfoxides (2) and sulfone derivatives (3). Conformations that allow for stabilizing stereoelectronic (σC-H → σ?C-F) and electrostatic (Fδ-...Sδ+) interactions predominate: this is consistent with the Sulfur-Fluorine Gauche Effect. The molar fractions (χ) of the two possible gauche conformers correlate linearly with the electron-withdrawing aptitude of the para-substituent, rendering the system ideally suited for a Hammett-type analysis. Despite the clear influence that the remote para-substituents have on conformer population, this is superseded by the oxidation state on sulfur (II, IV, VI), where an increased preference for the gauche conformer follows the trend: sulfide sulfone sulfoxide. It is envisaged that this proof of concept in controlling conformer population, either by proximal (oxidation state) or remote tuning (para-substituent), will find application in molecular design.
