Helv. Chim. Acta 2021, 104, e2000218
Zürich for funding. C. R. P. and D. B. thank Prof.
Hansjörg Grützmacher for his valuable insight, sugges-
tions, and generous donation of white phosphorus.
General Procedures for the Synthesis of R2P(=O)F Com-
pounds
Procedure for Compounds 21, 23, 25, and 26. The
appropriate phosphine oxide R2P(=O)H (0.5 mmol) was
added to an oven-dried vial equipped with a stirring
bar; the vessel was then transported inside a glove
Author Contribution Statement
box under N2 atmosphere. TCICA (3.8 mg, 0.17 mmol, D. B. optimized the reaction conditions, conceived/
0.33 equiv.), potassium fluoride (0.12 g, 2.0 mmol, performed the experiments, and assisted with data
4.0 equiv.) and (D3)MeCN (2.0 mL) were added to the compilation; F. B., N. B., and L. W. performed experi-
reaction vessel, which was then sealed with a cap with ments and assisted with data compilation; C. R. P.
septum using a crimper. The mixture was stirred obtained the initial proof of concept for TCICA
vigorously at room temperature overnight. After 16 h, reactivity and wrote/edited the manuscript.
an aliquot of the mixture was passed through a PTFE
syringe filter, and an NMR sample was prepared with
0.5 mL of the filtered aliquot. The crude mixture was
then filtered through a glass frit filter, and the volatiles
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was then dissolved in a hexane/dichloromethane 9:1
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Procedure for Compounds 22 and 24. The appro-
priate phosphine oxide R2P(=O)H (0.5 mmol) was
added to an oven-dried vial equipped with a stirring
bar; the vessel was then transported inside a glove
box under N2 atmosphere. TCICA (0.06 g, 0.25 mmol,
0.5 equiv.), potassium fluoride (0.12 g, 2.0 mmol,
4.0 equiv.) and (D3)MeCN (2.0 mL) were added to the
reaction vessel, which was then sealed with a cap with
septum using a crimper. The mixture was stirred
vigorously at room temperature overnight. After 16 h,
an aliquot of the mixture was passed through a PTFE
syringe filter, and an NMR sample was prepared with
0.5 mL of the filtered aliquot. The crude mixture was
then filtered through a glass frit filter, and the volatiles
were removed under reduced pressure. The residue
was then dissolved in a hexane/dichloromethane 1:1
mixture, and purified by flash chromatography, with a
3:2 hexane/ethyl acetate mixture employed as eluent.
The fractions containing the product were then
collected and evaporated under reduced pressure to
yield the product as an air-stable solid.
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Acknowledgements
The authors thank Prof. Antonio Togni for generous
use of lab equipment and ETH facilities, as well as ETH
(6 of 7) e2000218
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