Liquid-Assisted Grinding Accelerating the Defluorinative Coupling of gem-Difluoroalkenes under Ball-Milling Conditions

We disclose a rapid and versatile mechanochemical method coupling gem-difluoroalkenes with thiols, yielding Z-selective monofluorovinyl sulfides. Operating solvent-free, the reaction completes within 30 s, accommodating various nucleophiles (P, N, and O) and overcoming F-elimination to provide α, α-difluoroalkylthioethers under base-free conditions. Mechanistic investigations indicate that the base DBU abstracts a proton from the thiol, with the formation of Z-configuration being slightly more energetically favorable in kinetics. The protocol demonstrates good scalability, achieving gram-scale production with consistent Z-selectivity.