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Updated: Sep 26, 2025

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Ethynyl-SF4-Pyridines: Reagents for SF4-Alkynylation to Carbonyl Compounds
Kentaro Iwaki1, Koki Maruno1, Osamu Nagata2
1Department of Nanopharmaceutical Sciences & Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Abstract:
The trans-tetrafluoro-λ6-sulfanyl (SF4) unit is medicinally attractive because of its high electronegativity, lipophilicity, and unique hypervalent structure. The trans-SF4 unit can characteristically connect two independent molecules linearly. However, there is no example of the use of this unit for medicinal chemistry due to difficulties in synthesis. We report the first synthesis of (ethynyl-trans-tetrafluoro-λ6-sulfanyl)pyridines (t-ethynyl-SF4-pyridines) and their use as versatile reagents for the first direct SF4-alkynylation to carbonyl compounds. The addition reaction of t-ethynyl-SF4-pyridines to the carbonyl group in the presence of MeLi smoothly afforded pyridine-SF4-propargylic tertiary and secondary alcohols in high yields.
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