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Updated: Sep 7, 2025
Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Covalent triflates as synthons for silolyl- and germolyl cations
Wiebke Marie Wohltmann1, Marc Schmidtmann1, Thomas Müller1
1Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany. thomas.mueller@uni-oldenburg.de.
Abstract:
The synthesis of 1-silolyl and 1-germolyl triflates from the corresponding chlorides by salt metathesis reaction is reported. These covalent triflates are ideal starting materials for the preparation of ionic silolyl- and germolyl-imidazolium triflates by their reaction with N-heterocyclic carbenes. Similarily, ionic silolyl- and germolyl-oxophosphonium triflates are obtained by substitution of the triflate group by triethylphosphane oxide Et3PO. The analysis of their 31P NMR chemical shifts according to the Gutmann-Beckett method reveal the high Lewis acidity of the underlying silolyl and germolyl cations. Further analysis of structural and NMR parameters of the silolyl- and germolyl-imidazolium and oxophosphonium triflates indicates that these compounds are covalently bonded silole and germole derivatives with insignificant contributions from silolyl- or germolyl cations. Silolyl and germolyl triflates are however synthetic equivalents of these cations and might serve as a source for electrophilic silolyl and germolyl units.
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