10.1002/anie.201701570
Angewandte Chemie International Edition
COMMUNICATION
SynPhos 307616), and MINECO of Spain (project CTQ2014-
57393-C2-1-P, FEDER funds).
Keywords: Lewis acids • phosphorus • C-H activation • chelates
• non-covalent interactions • fluoride complexation
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Scheme 3. Silylotrifluoromethylation of selected aldehydes using [3-F]OTf as
catalyst; [a] after 3 h reaction time; isolated yields.
spectroscopy). In contrast, using neutral water (pH = ~7) under
same conditions, almost no consumption of [3-F]+ is observed
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[3-F]+ can be prepared starting from “wet” fluoride sources and
shows reversible F– complexation, it might be applicable as a con-
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aldehydes with Me3SiCF3 to selectively yield the corresponding
silyl ethers 4a-g in less than 1 h (Scheme 3; 4g: 3 h for quantita-
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show complete consumption of [3-F]+ and quantitative regenera-
tion of 32+.
In conclusion, the highly fluorophilic tri(phosphonio)methanide di-
cation 32+ was synthesized starting from the triflyloxyphospho-
nium dication 12+ that eliminates HOTf at elevated temperatures.
The reaction mechanism to form 32+ was investigated by DFT and
ab initio calculations and was identified as an electrophilic aro-
matic substitution (SEAr) reaction. Dication 32+ is capable for se-
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system (H2O/CHCl3) to give [3-F]+. Due to reversible fluoride com-
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Acknowledgements
This work was supported by the Fonds der Chemischen Industrie
(FCI, scholarship for F.H.) the European research council (ERC,
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