A scalable straightforward synthesis of monofluoro- and difluoromethyl triflate CF SO OCH F (M ) and CF SO OCHF (M ) through electrochemical fluorination (ECF, Simons process) of methyl triflate M in anhydrous hydrogen fluoride at nickel anodes is presented. The ECF method is also feasible for the preparation of the deuterated analogues CF SO OCD F (M ) and CF SO OCDF (M ). Surprisingly, no H/D exchange occurs during ECF of CF SO OCD (M ); this provides further evidence for a NiF /NiF -mediated ECF mechanism.
View Article and Find Full Text PDFRoom temperature ionic liquids of cyclic sulfonimide anions cPFSI (ring size: = 4-6) with the cations [EMIm] (1-ethyl-3-methylimidazolium), [BMIm] (1-butyl-3-methylimidazolium) and [BMPL] (BMPL = 1-butyl-1-methylpyrrolidinium) have been synthesized. Their solid-state structures have been elucidated by single-crystal X-ray diffraction and their physicochemical properties (thermal behaviour and stability, dynamic viscosity and specific conductivity) have been assessed. In addition, the ion diffusion was studied by pulsed field gradient stimulated echo (PFGSTE) NMR spectroscopy.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2019
Bidentate boron Lewis acids based on 1,8-diethynylanthracene were synthesised in two steps by initial stannylation of the terminal alkynes and subsequent tin-boron exchange with different chloroboranes. The reactions were very selective, and the target compounds were obtained in high purity and good to excellent yields. Complexation experiments of 1,8-bis[(diphenylboranyl)ethynyl]anthracene with nitrogen bases (pyridine, pyrimidine, TMEDA) afforded three stable adducts, which were structurally characterised by X-ray diffraction.
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