Synthesis of Sulfonyl, Sulfonimidoyl, and Sulfoxyl Fluorides under Solvent-Free Mechanochemical Conditions in a Mixer Mill by Imidazole-to-Fluorine Exchange
Marco T. Passia, Mostafa M. Amer, Joachim Demaerel, Carsten Bolm
Abstract
A sustainable, mechanochemical procedure for the synthesis of sulfur(VI) fluorides starting from readily available sulfur(VI) 2-methylimidazoles as stable S(VI) precursors has been developed. The transformation proceeds with potassium bifluoride (KHF 2 ) as the fluorine source in the presence of acetic acid (AcOH) in a mixer mill under solvent-free conditions. The corresponding sulfonyl, sulfonimidoyl, and sulfoxyl fluorides are formed in good to excellent yields. Compared with the solution-based counterpart, the reaction times are shorter. This environmentally benign mechanochemical approach exhibits significant ecological advantages and requires less resources for the optimized purification by simple silica plug filtration.