Fluoromethyl Triflate and Fluoromethyl Fluorosulfonate: Easily Accessible and Powerful Fluoromethylation Reagents.

Fluoromethyl triflate (superfluoromethyl, SFM, FCH2OSO2CF3) and fluoromethyl fluorosulfonate (magic fluoromethyl, MFM, FCH2OSO2F) are two easily synthesized, highly effective and non-ozone depleting fluoromethylation reagents. They are analogous to the well-known and widely used methylation re-agents CH3OSO2CF3 and CH3OSO2F. Both SFM and MFM have been fully characterized by multinuclear NMR spectroscopy (1H, 13C, 17O, 19F, 33S). Their structures have been determined in the solid state on in situ grown crystals by X-ray diff-raction and in the gas phase by electron diffraction. The fluoromethylation efficiency of SFM and MFM was shown by reaction with chalcogen nucleophiles of differing nucleophilicity. All fluoromethylated products were isolated as pure com-pounds and charac-terized by NMR and vibrational spec-troscopy, as well as in some cases by single crystal X-ray diffraction.