- SYNTHESE DE FLUORO-2 THIOCYANATES
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2-Fluorinated thiocyanate compounds have been prepared by action of KSCN on a homologous series of 2-fluorotosylates in ethanol at about 100 deg C.The isomerization giving isothiocyanic derivatives does not take place under these conditions.The analysis o
- Ellouze, W.,Chaabouni, M. M.,Baklouti, A.
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- The influence of electronic perturbations on the Sulfur-Fluorine Gauche Effect Dedicated to Prof. Dr. Antonio Togni on the occasion of his 60th birthday.
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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 Despite the clear influence that the remote para-substituents have on conformer population, this is superseded by the oxidation state on sulfur (II, IV, VI), where an increased preference for the gauche conformer follows the trend: sulfide sulfone sulfoxide.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.
- Thiehoff, Christian,Schifferer, Lukas,Daniliuc, Constantin G.,Santschi, Nico,Gilmour, Ryan
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supporting information
p. 121 - 126
(2016/01/25)
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