A study of proposed intermediates in the deoxofluorination of carbonyl groups by SF4
Date
2018
Authors
Stuart, Daniel
University of Lethbridge. Faculty of Arts and Science
Journal Title
Journal ISSN
Volume Title
Publisher
Lethbridge, Alta. : Universtiy of Lethbridge, Department of Chemistry and Biochemistry
Abstract
The [SF4·O=C(CH3)2]2 and SF4·[O=C(CH3)2]2 adducts were synthesized and characterized at low temperature (LT) using Raman spectroscopy and, in the case of [SF4·O=C(CH3)2]2, single-crystal X-ray diffraction. The X-ray crystal structure of SF4·(O=C10H14)·(HF) was obtained, showing F4S---F−H---O=C10H14 interactions.
Adducts of [SF3]+ with acetone, cyclopentanone, and 2-adamantanone were shown by 19F and 1H NMR spectroscopy to exist in solutions below −40 °C. The proposed [SF3·{O=C(CH3)2}3]+ cation was observed at LT by reacting [SF3][AsF6] with excess acetone. Above −40 °C SF4 formation was observed.
Protonated ketones, [HO=R]+ (R = C(CH3)2, C5H8, C10H14), and aldehydes, [H(O=CHC6H5)2]+ and [H(O=CHCH3)x]+ (x = 1 or 2), were isolated and characterized in the solid state for the first time. NBO analyses were used to quantify the increase in electrophilicity of the oxonium cations.
The AsF5·O=R (R = C(CH3)2, C5H8, C10H14) adducts were synthesized and characterized in solution and solid state using LT NMR and Raman spectroscopies, respectively.
Description
Keywords
Organofluorine compounds , Sulfur tetrafluoride , Carbonyl compounds , Lewis acids , deoxofluorination reactions , Lewis acid-base reactions , organic carbonyl compounds , organofluorine chemistry